Ce que dit la recherche

Nuits chaudes

Pas encore de méta-analyse, mais une revue systématique de 36 études et les données de capteurs de centaines de milliers de personnes concordent : plus la nuit est chaude, plus le sommeil est court et mauvais, d’environ 15 à 17 minutes lors des nuits très chaudes. La plupart des logements se chauffent mais ne se refroidissent pas, c’est pourquoi seules les nuits chaudes comptent dans la prévision.

Aucune méta-analyse trouvée.

1. Revue systématique36 articles (no pooling: designs too varied)

   Chevance G, Minor K, Vielma C, et al. (2024). A systematic review of ambient heat and sleep in a warming climate. Sleep Medicine Reviews. doi.org/10.1016/j.smrv.2024.101915

   Higher outdoor or indoor temperatures are generally linked to worse sleep quality and quantity, more so in the hottest months, regions and vulnerable groups.

2. Grande étude, pas une méta-analyse317,758 users, about 165 million nights

   Lechat B, Toson B, Scott H, et al. (2026). How do we sleep while our beds are burning? High ambient temperatures are associated with substantial sleep loss. Sleep. doi.org/10.1093/sleep/zsaf323

   At the 99th vs 50th temperature percentile (27.3 °C vs 12.2 °C), sleep was 15.2–16.9 min shorter; risk of sleeping under 6 h rose by 40–43%.

3. Grande étude, pas une méta-analyse214,445 participants, about 23 million days

   Li A, Luo H, Zhu Y, et al. (2025). Climate warming may undermine sleep duration and quality in repeated-measure study of 23 million records. Nature Communications. doi.org/10.1038/s41467-025-57781-y

   Each 10 °C rise in daily mean temperature: 20.1% higher odds of insufficient sleep and 9.67 min less total sleep.

4. Grande étude, pas une méta-analyse47,628 adults, more than 7 million sleep records, 68 countries

   Minor K, Bjerre-Nielsen A, Jonasdottir SS, et al. (2022). Rising temperatures erode human sleep globally. One Earth. doi.org/10.1016/j.oneear.2022.04.008

   Higher temperatures erode sleep; suboptimal temperatures are projected to cost 50–58 hours of sleep per person per year by 2099.

Jour de la semaine

Le week-end, on se couche plus tard et on dort plus longtemps : jusqu’à une heure de plus chez les grands adolescents et 20 à 35 minutes chez les adultes, selon des données regroupées et 73 millions de nuits mesurées. Aucun travail ne confirme un effet propre au « dimanche soir », donc la prévision ne valorise que les nuits avant un jour de repos.

1. Méta-analyse79 studies in the meta-analysis (18 on weekday vs weekend)

   Galland BC, Short MA, Terrill P, et al. (2018). Establishing normal values for pediatric nighttime sleep measured by actigraphy: a systematic review and meta-analysis. Sleep. doi.org/10.1093/sleep/zsy017

   At ages 15–18, total sleep on weekends or non-school days was 56 min longer; sleep onset about 1 h and wake-up about 2 h later.

2. Méta-analyse41 surveys

   Gradisar M, Gardner G, Dohnt H (2011). Recent worldwide sleep patterns and problems during adolescence: a review and meta-analysis of age, region, and sleep. Sleep Medicine. doi.org/10.1016/j.sleep.2010.11.008

   Weekend bedtimes were 2+ hours later worldwide, with more total sleep.

3. Méta-analyse37 studies

   Rodríguez Ferrante G, Lee F, Leone MJ (2024). Effects of school start time and its interaction with the solar clock on adolescents' chronotype and sleep: a systematic review and meta-analysis. Sleep Medicine Reviews. doi.org/10.1016/j.smrv.2024.101988

   Later school start times were linked to longer weekday sleep, later sleep timing and less social jetlag.

4. Méta-analyse30 studies, 92,977 data points

   Olds T, Blunden S, Petkov J, Forchino F (2010). The relationships between sex, age, geography and time in bed in adolescents: a meta-analysis of data from 23 countries. Sleep Medicine Reviews. doi.org/10.1016/j.smrv.2009.12.002

   Time in bed fell by 14 min per year of age on school days and 7 min on non-school days.

5. Grande étude, pas une méta-analyse116,879 adults, about 73 million nights

   Scott H, Lechat B, Sansom K, et al. (2025). Variations in sleep duration and timing: weekday and seasonal variations in sleep are common in an analysis of 73 million nights from an objective sleep tracker. Sleep. doi.org/10.1093/sleep/zsaf099

   Sleep was 20–35 min longer on weekends; bedtime 30–40 min and wake-up 60–80 min later.

Changement d’heure

Aucune méta-analyse n’a encore regroupé les données de sommeil autour des changements d’heure. Les grandes études par capteurs s’accordent sur la nuit même : environ une heure de sommeil en moins au passage à l’heure d’été et une demi-heure de plus en automne, avec un rattrapage partiel les jours suivants.

Aucune méta-analyse trouvée.

1. Grande étude, pas une méta-analyse11,780 adults

   de Lange MA, Richmond RC, Birnie K, et al. (2025). The effects of daylight saving time clock changes on accelerometer-measured sleep duration in the UK Biobank. Journal of Sleep Research. doi.org/10.1111/jsr.14335

   Spring: sleep on the clock-change night 65 min shorter (95% CI −72 to −58). Autumn: 33 min longer (27–39).

2. Grande étude, pas une méta-analyse24,250 wearable users, 10,350,760 sleep episodes

   Heacock RM, Capodilupo ER, Czeisler MÉ, et al. (2022). Sleep and Alcohol Use Patterns During Federal Holidays and Daylight Saving Time Transitions in the United States. Frontiers in Physiology. doi.org/10.3389/fphys.2022.884154

   Significant differences in sleep compared with baseline on most clock-change transitions.

3. Revue systématique157 studies, 36 countries (no pooling: data too varied)

   Steponenaite A, Wallraff JP, Wild U, et al. (2026). A systematic review of epidemiological studies into daylight-saving time & health identifying beneficial & adverse effects. European Journal of Epidemiology. doi.org/10.1007/s10654-026-01372-8

   Standard time may be linked to shorter winter sleep; limited studies prevent clear conclusions on other sleep measures.

4. Revue systématique27 studies (no pooling)

   Romigi A, Franco V, Scoditti E, et al. (2025). The effects of daylight saving time and clock time transitions on sleep and sleepiness: a systematic review. Sleep Medicine Reviews. doi.org/10.1016/j.smrv.2025.102161

   The switch to DST was linked to worse sleep duration and quality and more sleepiness, especially in evening types; findings were heterogeneous.

Grands événements nocturnes

Il n’existe pas de méta-analyse, mais de grands jeux de données de capteurs montrent des effets nets sur une nuit : 13 à 16 minutes de sommeil en moins après le vote du Brexit et l’élection américaine de 2016, et un coucher environ une heure et demie plus tard le soir du Nouvel An. La prévision utilise un calendrier de ces nuits établi à la main.

Aucune méta-analyse trouvée.

1. Grande étude, pas une méta-analyse10.5 million sleep records from more than 69,000 app users

   Anýž J, Bakštein E, Dudysová D, et al. (2019). No wink of sleep: Population sleep characteristics in response to the brexit poll and the 2016 U.S. presidential election. Social Science & Medicine. doi.org/10.1016/j.socscimed.2018.12.024

   Mean sleep fell by 16 min 21 s in the UK after the Brexit vote and by 12 min 49 s in the US after the 2016 election.

2. Grande étude, pas une méta-analyse24,250 wearable users, 10,350,760 sleep episodes

   Heacock RM, Capodilupo ER, Czeisler MÉ, et al. (2022). Sleep and Alcohol Use Patterns During Federal Holidays and Daylight Saving Time Transitions in the United States. Frontiers in Physiology. doi.org/10.3389/fphys.2022.884154

   On New Year’s Eve sleep onset was 88.9 min later, wake time 78.1 min later, and alcohol use 138% more common.

Ramadan

Pendant le ramadan, le sommeil nocturne est régulièrement plus court (d’environ 0,8 heure dans la plus grande méta-analyse) et plus tardif, avec davantage de siestes. Les méta-analyses sont petites et portent surtout sur de jeunes hommes et des sportifs, l’effet sur l’ensemble de la population est donc moins certain. La prévision l’applique dans les pays à majorité musulmane.

1. Méta-analyse24 studies; 646 participants; 12 countries

   Faris MAE, Jahrami HA, Alhayki FA, et al. (2020). Effect of diurnal fasting on sleep during Ramadan: a systematic review and meta-analysis. Sleep and Breathing. doi.org/10.1007/s11325-019-01986-1

   Total sleep time fell from 7.2 h to 6.4 h (Hedges’ g −0.43); daytime sleepiness changed negligibly.

2. Méta-analyse18 papers; 298 participants

   Trabelsi K, Ammar A, Glenn JM, et al. (2022). Does observance of Ramadan affect sleep in athletes and physically active individuals? A systematic review and meta-analysis. Journal of Sleep Research. doi.org/10.1111/jsr.13503

   Sleep duration decreased (g −0.766); sleep quality score worsened from 4.05 to 5.35; daytime naps got longer.

3. Méta-analyse13 articles

   Trabelsi K, Bragazzi N, Zlitni S, et al. (2020). Observing Ramadan and sleep-wake patterns in athletes: a systematic review, meta-analysis and meta-regression. British Journal of Sports Medicine. doi.org/10.1136/bjsports-2018-099898

   Total sleep time decreased (effect size −0.97); daytime sleepiness unchanged.

4. Méta-analyse14 studies

   El-Jaziz A, Lotfi S (2025). Sleep Patterns Among Athletes and Non-Athletes During Ramadan intermittent fasting: Systematic Review, Meta-Analysis and Meta-Regression. Annali di Igiene. doi.org/10.7416/ai.2025.2675

   Sleep duration and efficiency were negatively affected; latency and disturbance were not.

5. Grande étude, pas une méta-analyse24,541 adults in 27 countries

   Khan MAB, BaHammam AS, Amanatullah A, et al. (2023). Examination of sleep in relation to dietary and lifestyle behaviors during Ramadan: A multi-national study using structural equation modeling among 24,500 adults amid COVID-19. Frontiers in Nutrition. doi.org/10.3389/fnut.2023.1040355

   Sleeping 7–9 h during Ramadan was associated with physical activity and plant protein intake; smoking with worse sleep.

Pollution de l’air

Des méta-analyses portant sur plus de quatre millions de personnes montrent que davantage de particules fines (PM2,5) et de NO2 s’accompagnent d’un risque de mauvais sommeil plus élevé d’environ 6 à 30 % par 10 µg/m³, et d’une apnée du sommeil plus sévère. Presque tout concerne l’exposition à long terme, la prévision n’accorde donc qu’un faible poids aux nuits polluées.

1. Méta-analyse11 studies; 3,328,183 participants

   Cao Z, Shi X, Sun L, et al. (2025). Association between exposure to air pollution and risk of Dyssomnia: a systematic review and meta-analysis. International Archives of Occupational and Environmental Health. doi.org/10.1007/s00420-025-02137-8

   Odds of sleep problems per 10 µg/m³: PM2.5 1.29, PM10 1.13, NO2 1.06, O3 1.16; SO2 not significant.

2. Méta-analyse25 studies; at least 1,262,210 adults

   Wang M, Cho Y, Li J (2025). Air pollution and sleep health in middle-aged and older adults: A systematic review and meta-analysis. Sleep Medicine Reviews. doi.org/10.1016/j.smrv.2025.102136

   Long-term exposure, per 10 µg/m³: PM2.5 OR 1.27, PM1 1.37, PM10 1.10; NO2 (per 5 µg/m³) 1.07; ozone not significant.

3. Méta-analyse20 studies (13 pooled)

   He Y, Wang S, Zhang T, et al. (2026). Does short- and long-term exposure to air pollution affect the risk of obstructive sleep apnea? A systematic review and meta-analysis. Sleep Medicine Reviews. doi.org/10.1016/j.smrv.2025.102225

   Per 10 µg/m³ PM2.5, the apnea-hypopnea index rose 2.25% short-term and 13.33% long-term (high certainty).

4. Méta-analyse10 studies

   Zhao Y, Zhang S, Guo L, et al. (2024). Association between Air Pollutants and the Risk of Sleep Disorders: A Systematic Review and Meta-analysis. Aerosol and Air Quality Research. doi.org/10.4209/aaqr.230197

   Per 10 µg/m³: PM2.5 OR 2.50 (an outlier compared with other meta-analyses), PM10 1.15, NO2 1.36.

5. Méta-analyse12 studies (4 pooled)

   Alrahbeni T, Gupta JK, Alkhouri A, et al. (2024). Association of air pollution with risk and severity of obstructive sleep apnea: A systematic review and meta-analysis. Neurotoxicology. doi.org/10.1016/j.neuro.2024.04.005

   No significant link with sleep apnea risk (PM2.5 OR 0.987, NO2 1.095), though several studies linked pollution to greater severity.

Pollen et rhume des foins

Les personnes allergiques au pollen rapportent systématiquement un sommeil moins bon, plus d’insomnie, de ronflements et de somnolence, dans des données portant sur des millions de personnes ; traiter le nez améliore le sommeil dans les essais. Les études portent sur l’allergie et non sur les comptes polliniques quotidiens, la prévision ne signale donc que les jours de pollen élevé.

1. Méta-analyse27 articles; 240,706,026 patients (19,444,043 with allergic rhinitis)

   Liu J, Zhang X, Zhao Y, et al. (2020). The association between allergic rhinitis and sleep: A systematic review and meta-analysis of observational studies. PLoS One. doi.org/10.1371/journal.pone.0228533

   Worse sleep quality, more sleep medication and lower sleep efficiency; associated with insomnia, snoring, sleep apnea and daytime sleepiness. Sleep duration did not differ. Certainty low to very low.

2. Méta-analyse49 studies; 18,269,265 individuals

   Safia A, Elhadi UA, Karam M, et al. (2024). A meta-analysis of the prevalence and risk of mental health problems in allergic rhinitis patients. Journal of Psychosomatic Research. doi.org/10.1016/j.jpsychores.2024.111813

   Among patients: poor sleep quality 48%, insomnia 36%, sleep under 7 h 59%; higher risk of insomnia and sleep impairment than controls.

3. Méta-analyse17 studies; 32,907 children

   Li Q, Zhong Q, Kong X, et al. (2026). Allergic rhinitis in children in relation to sleep breathing disorders: a meta-analysis. International Journal of Pediatric Otorhinolaryngology. doi.org/10.1016/j.ijporl.2026.112902

   Allergic rhinitis OR 2.24 in habitual snorers, 1.49 in sleep-disordered breathing, 1.23 in sleep apnea.

4. Méta-analyse12 studies; 19,203 participants

   Ferreira NB, Ponte A, Grande AC, et al. (2025). Frequency of obstructive sleep apnea in patients with asthma or allergic rhinitis: a systematic review and meta-analysis. Sleep Medicine. doi.org/10.1016/j.sleep.2025.106705

   Sleep apnea more frequent with allergic rhinitis (OR 2.4; 95% CI 1.1–5.3).

5. Méta-analyse44 studies; 6,086 participants

   Cao Y, Wu S, Zhang L, et al. (2018). Association of allergic rhinitis with obstructive sleep apnea: A meta-analysis. Medicine (Baltimore). doi.org/10.1097/MD.0000000000013783

   Children with sleep-disordered breathing had 2.12 times higher odds of allergic rhinitis.

Bruit nocturne

Le bruit des transports la nuit est l’un des facteurs de sommeil les mieux étudiés : le risque d’être très perturbé double environ tous les 10 dB, et les enregistrements en laboratoire confirment davantage de réveils. Pour les orages, le vent fort et les feux d’artifice, il n’existe pas d’étude dédiée, la prévision leur donne donc un faible poids.

1. Méta-analyse74 studies

   Basner M, McGuire S (2018). WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Effects on Sleep. International Journal of Environmental Research and Public Health. doi.org/10.3390/ijerph15030519

   Self-reported sleep disturbance per 10 dB night noise (when the question named noise): OR 1.94 aircraft, 2.13 road, 3.06 rail; awakenings per 10 dBA indoor peak: OR 1.35–1.36.

2. Méta-analyse68 observational studies, 152 effect sizes

   Li Z (2026). Environmental Noise Exposure and the Risk of Sleep Disturbance: A Systematic Review and Meta-Analysis. Noise & Health. doi.org/10.4103/nah.nah_222_25

   Correlation with sleep disturbance: aircraft r = 0.26, railway r = 0.21, road r = 0.15 (high certainty; very high heterogeneity).

3. Méta-analyse36 studies, about 173,000 responses

   Smith MG, Cordoza M, Basner M (2022). Environmental Noise and Effects on Sleep: An Update to the WHO Systematic Review and Meta-Analysis. Environmental Health Perspectives. doi.org/10.1289/EHP10197

   Odds of being highly sleep disturbed per 10 dB night noise: aircraft 2.18, road 2.52, railway 2.97.

4. Méta-analyse15 articles

   Godono A, Ciocan C, Clari M, et al. (2023). Association between exposure to wind turbines and sleep disorders: A systematic review and meta-analysis. International Journal of Hygiene and Environmental Health. doi.org/10.1016/j.ijheh.2023.114273

   Sleep disorders in 34% of people living near wind turbines, falling with distance; evidence quality poor.

5. Méta-analyse9 studies reviewed, 5 meta-analysed

   Liebich T, Lack L, Hansen K, et al. (2021). A systematic review and meta-analysis of wind turbine noise effects on sleep using validated objective and subjective sleep assessments. Journal of Sleep Research. doi.org/10.1111/jsr.13228

   No significant effect on objectively measured sleep (e.g. sleep efficiency g = −0.25, not significant).

Humidité

Il n’existe pas de preuves regroupées sur l’humidité. De grands jeux de données suggèrent qu’un air très sec ou très humide va avec un sommeil plus court ou plus haché, et l’humidité aggrave la chaleur car la transpiration refroidit moins. La prévision ne compte donc l’air lourd que les nuits chaudes, avec un faible poids.

Aucune méta-analyse trouvée.

1. Grande étude, pas une méta-analyse47,628 adults, 68 countries

   Minor K, Bjerre-Nielsen A, Jonasdottir SS, et al. (2022). Rising temperatures erode human sleep globally. One Earth. doi.org/10.1016/j.oneear.2022.04.008

   Humidity results are not stated in the abstract; a later review describes both low and high humidity as reducing sleep duration in this dataset.

2. Grande étude, pas une méta-analyse8,611 sleep-clinic patients (mostly with sleep apnea)

   Tung NT, Lee YL, Liu WT, et al. (2025). Impact of PM2.5, relative humidity, and temperature on sleep quality: a cross-sectional study in Taipei. Annals of Medicine. doi.org/10.1080/07853890.2024.2448733

   Higher relative humidity was associated with changes in non-REM sleep stages and more arousals in all seasons.

Pleine lune

Il n’existe pas de méta-analyse sur la lune et le sommeil. Quelques petites études en laboratoire ont trouvé un sommeil un peu plus léger ou plus court vers la pleine lune, mais les plus grands jeux de données ne trouvent aucun effet ou environ 5 minutes, et un biais de publication a été documenté. La prévision affiche la lune mais ne lui donne presque aucun poids.

Aucune méta-analyse trouvée.

1. Grande étude, pas une méta-analyse5,812 children, 12 countries, 33,710 accelerometer days

   Chaput JP, Weippert M, LeBlanc AG, et al. (2016). Are Children Like Werewolves? Full Moon and Its Association with Sleep and Activity Behaviors in an International Sample of Children. Frontiers in Pediatrics. doi.org/10.3389/fped.2016.00024

   Sleep was about 5 min shorter at full moon than at new moon; no other differences.

2. Grande étude, pas une méta-analyse2,125 adults with home polysomnography

   Haba-Rubio J, Marques-Vidal P, Tobback N, et al. (2015). Bad sleep? Don't blame the moon! A population-based study. Sleep Medicine. doi.org/10.1016/j.sleep.2015.08.002

   No significant differences between lunar phases in subjective or objective sleep.

3. Grande étude, pas une méta-analysePooled reanalysis of sleep-lab datasets (no abstract)

   Cordi M, Ackermann S, Bes FW, et al. (2014). Lunar cycle effects on sleep and the file drawer problem. Current Biology. doi.org/10.1016/j.cub.2014.05.017

   No statistically relevant link between sleep and lunar phase; publication bias may explain earlier positive findings.

4. Grande étude, pas une méta-analyseSmall laboratory sample (not stated in abstract)

   Cajochen C, Altanay-Ekici S, Münch M, et al. (2013). Evidence that the lunar cycle influences human sleep. Current Biology. doi.org/10.1016/j.cub.2013.06.029

   Around full moon, deep-sleep EEG activity was 30% lower and total sleep 20 min shorter. The most-cited positive study.

Stress collectif

Pendant la pandémie de COVID-19, environ un cinquième à deux cinquièmes de la population avaient des troubles du sommeil selon des méta-analyses portant sur jusqu’à un demi-million de personnes, et les confinements les ont aggravés. Après un séisme ou une guerre, de grandes études montrent des hausses nettes, souvent temporaires, de l’insomnie. Nous n’avons pas encore de signal quotidien fiable de stress lié à l’actualité : ce facteur figure ici mais n’est pas utilisé dans la prévision.

1. Méta-analyse250 studies; 493,475 participants; 49 countries

   Jahrami HA, Alhaj OA, Humood AM, et al. (2022). Sleep disturbances during the COVID-19 pandemic: A systematic review, meta-analysis, and meta-regression. Sleep Medicine Reviews. doi.org/10.1016/j.smrv.2022.101591

   Global prevalence of sleep disturbances 40.49%; general population 36.73%; higher during lockdown (42.49% vs 37.97%).

2. Méta-analyse177 papers; 345,270 participants; 39 countries

   Alimoradi Z, Broström A, Tsang HWH, et al. (2021). Sleep problems during COVID-19 pandemic and its' association to psychological distress: A systematic review and meta-analysis. EClinicalMedicine. doi.org/10.1016/j.eclinm.2021.100916

   Sleep problems in 18% of the general population, 31% of healthcare workers and 57% of COVID-19 patients.

3. Méta-analyse154 studies

   Ceolin C, Limongi F, Siviero P, et al. (2024). Changes in Sleep Duration and Sleep Timing in the General Population from before to during the First COVID-19 Lockdown: A Systematic Review and Meta-Analysis. International Journal of Environmental Research and Public Health. doi.org/10.3390/ijerph21050583

   Sleep duration rose slightly during lockdown (SMD 0.25); sleep timing was moderately delayed and napping increased.

4. Méta-analyse139 studies

   Scarpelli S, Zagaria A, Ratti PL, et al. (2022). Subjective sleep alterations in healthy subjects worldwide during COVID-19 pandemic: A systematic review, meta-analysis and meta-regression. Sleep Medicine. doi.org/10.1016/j.sleep.2022.07.012

   Pooled PSQI 6.73 (in the poor-sleep range); pooled insomnia severity 8.44 (subthreshold).

5. Méta-analyse66 studies; 42,956 participants

   Carpinelli LP, Gauer LE, Soares VHD, et al. (2026). Insomnia and poor sleep quality in refugee and asylum-seeking populations: A systematic review and meta-analysis. PLoS ONE. doi.org/10.1371/journal.pone.0352964

   Sleep problems in 43.2% of adults and 36.4% of children; pooled insomnia severity 13.76.

6. Grande étude, pas une méta-analyseNationwide random samples of about 1,250 people per wave

   Itoh Y, Takeshima M, Kaneita Y, et al. (2022). Associations Between the 2011 Great East Japan Earthquake and Tsunami and the Sleep and Mental Health of Japanese People: A 3-Wave Repeated Survey. Nature and Science of Sleep. doi.org/10.2147/nss.s338095

   Insomnia rose from 11.7% to 21.2% four months after the disaster and returned to 10.6% at 18 months.

7. Grande étude, pas une méta-analyseNational survey N = 6,474 plus three further samples

   Zak U, Choshen-Hillel S, Hochner H, et al. (2025). Tired of war: Changes in the sleep of the Israeli civilian population in the wake of the Israel-Hamas war. International Journal of Clinical and Health Psychology. doi.org/10.1016/j.ijchp.2025.100596

   Short sleep (under 6 h) up 19–22%, clinical insomnia up 16–19%; most effects persisted at 6 months.

Lumière du jour et saison

On dort un peu plus pendant les mois sombres et moins quand les jours sont longs, et davantage de lumière le soir (par exemple à l’ouest d’un fuseau horaire) va avec un sommeil plus court. Les effets sont faibles, environ 10 à 20 minutes, et les rares méta-analyses se contredisent : la prévision ne l’utilise pas encore.

1. Méta-analyse18 studies, 986 participants

   Shao Y, Li Y, Wang N, et al. (2024). Effect of daily light exposure on sleep in polar regions: A meta-analysis. Journal of Sleep Research. doi.org/10.1111/jsr.14144

   Intense summer light reduced sleep time and efficiency; moderate spring/autumn light delayed sleep.

2. Méta-analyse17 studies (11 on season), 1,951 adults

   Ferguson T, Curtis R, Fraysse F, et al. (2021). Annual, seasonal, cultural and vacation patterns in sleep, sedentary behaviour and physical activity: a systematic review and meta-analysis. BMC Public Health. doi.org/10.1186/s12889-021-11298-3

   Sleep was highest in autumn (+12 min above the yearly mean), but not statistically significant.

3. Méta-analyseNot stated in abstract

   Weaver RG, Hensing C, Armstrong B, Adams EL, Beets M (2022). Seasonal Shifts in Children's Sedentary Behaviors, Physical Activity, and Sleep: A Systematic Review and Meta-Analysis. Pediatric Clinics of North America. doi.org/10.1016/j.pcl.2022.04.005

   The authors note a paucity of data on seasonal variation in sleep.

4. Méta-analyse53 studies, 1,154 participants

   van Maanen A, Meijer AM, van der Heijden KB, Oort FJ (2016). The effects of light therapy on sleep problems: A systematic review and meta-analysis. Sleep Medicine Reviews. doi.org/10.1016/j.smrv.2015.08.009

   Light therapy improved sleep problems overall (g = 0.39) and insomnia (g = 0.47). Indirect evidence: light as treatment.

5. Grande étude, pas une méta-analyse416,731 adults

   DelRosso LM, Vodapally M (2026). Seasonal and geographic variation in sleep duration among U.S. adults: Evidence from the 2022 BRFSS. Chronobiology International. doi.org/10.1080/07420528.2025.2611866

   Monthly variation was modest (7.82 h in April to 8.13 h in January); latitude and time-zone differences were small.

6. Grande étude, pas une méta-analyseUS time zone border comparison

   Giuntella O, Mazzonna F (2019). Sunset time and the economic effects of social jetlag: evidence from US time zone borders. Journal of Health Economics. doi.org/10.1016/j.jhealeco.2019.03.007

   One extra hour of evening natural light reduced sleep by 19 min on average.

Fronts météo et pression

Beaucoup de gens disent que les fronts perturbent leur sommeil, mais aucune méta-analyse n’a étudié la pression et le sommeil, et les rares études directes sont petites et contradictoires. La pression est un peu liée à la migraine, pas de façon constante à la douleur. La prévision signale les fortes variations de pression pour que vos votes testent l’idée, sans effet sur le score.

1. Méta-analyse31 studies (about migraine, not sleep)

   Li S, Liu Q, Ma M, et al. (2025). Association between weather conditions and migraine: a systematic review and meta-analysis. Journal of Neurology. doi.org/10.1007/s00415-025-13078-0

   Ambient pressure was significantly associated with migraine attacks (OR 1.07, 95% CI 1.01–1.15).

2. Méta-analyse11 studies, 15,315 participants (about pain, not sleep)

   Ferreira ML, Hunter DJ, Fu A, et al. (2024). Come rain or shine: Is weather a risk factor for musculoskeletal pain? A systematic review with meta-analysis of case-crossover studies. Seminars in Arthritis and Rheumatism. doi.org/10.1016/j.semarthrit.2024.152392

   No association between air pressure and rheumatoid arthritis, knee or low back pain.

3. Grande étude, pas une méta-analyse7,523 sleep-lab patients

   Cassol CM, Martinez D, da Silva FABS, et al. (2012). Is sleep apnea a winter disease?: meteorologic and sleep laboratory evidence collected over 1 decade. Chest. doi.org/10.1378/chest.11-0493

   Sleep apnea severity correlated inversely with temperature and directly with atmospheric pressure.

4. Grande étude, pas une méta-analyse537 sleep-lab patients

   Doherty MJ, Youn CE, Haltiner AM, et al. (2010). Do weather-related ambient atmospheric-pressure changes influence sleep disordered breathing?. Journal of Clinical Sleep Medicine. doi.org/10.5664/jcsm.27764

   Obstructive apnea rose with lower pressure, the opposite direction to the study above.

Météo spatiale (orages géomagnétiques)

Nous n’avons trouvé aucune étude mesurant le sommeil humain en fonction de l’activité géomagnétique, seulement de petites études anciennes signalant une mélatonine (hormone du sommeil) plus basse lors de perturbations géomagnétiques. La prévision affiche l’indice Kp à titre d’information, sans effet sur le score.

Aucune méta-analyse trouvée.

1. Grande étude, pas une méta-analyse153 utility workers (melatonin measured, not sleep)

   Burch JB, Reif JS, Yost MG (2008). Geomagnetic activity and human melatonin metabolite excretion. Neuroscience Letters. doi.org/10.1016/j.neulet.2008.04.031

   Higher geomagnetic activity was associated with lower nocturnal melatonin-metabolite levels.

2. Grande étude, pas une méta-analyse132 utility workers (melatonin measured, not sleep)

   Burch JB, Reif JS, Yost MG (1999). Geomagnetic disturbances are associated with reduced nocturnal excretion of a melatonin metabolite in humans. Neuroscience Letters. doi.org/10.1016/s0304-3940(99)00308-0

   Overnight melatonin-metabolite excretion was lower on geomagnetically disturbed days.

3. Grande étude, pas une méta-analyse25 healthy subjects (melatonin measured, not sleep)

   Weydahl A, Sothern RB, Cornélissen G, et al. (2001). Geomagnetic activity influences the melatonin secretion at latitude 70 degrees N. Biomedicine & Pharmacotherapy. doi.org/10.1016/s0753-3322(01)90006-x

   Large geomagnetic changes significantly decreased salivary melatonin.