Spring brings longer days and warmer weather as clocks shift to daylight savings. Yet research reveals a hidden downside: we sleep less as summer nears. Bodies crave more rest during dark winter months.breathingandsleepcenter+1
Scientists tracked 188 urban patients with sleep issues. Even under artificial lights, participants slept an hour longer in December than June. Their REM sleep—the dreaming phase tied to circadian rhythms—extended 30 minutes in winter.bigthink+1
Berlin’s St Hedwig Hospital sleep expert Dieter Kunz led the study. Natural light strongly influences our 24-hour sleep-wake cycle via melatonin, the hormone that triggers drowsiness. Artificial light before bed suppresses it, but seasons still dominate.pubmed.ncbi.nlm.nih+1
Winter’s short days boost melatonin, mimicking “hibernation.” Urban dwellers feel it too—falling asleep earlier, waking later. Summer’s long light delays melatonin, shortens REM, and cuts total sleep.pmc.ncbi.nlm.nih+1
Kunz predicts even bigger swings for those in natural light. Circadian clocks adapt: summer advances wake times; winter delays them.
