Why Rainy Days Make Us Tired

Rain may make you feel tired, but it doesn't really help you get a
good night's sleep. In fact, sunny weather brings more restful nights,
according to research done at the University of Rochester Sleep
Laboratory in New York. When the clouds go away, not only do you sleep
more soundly, you are more likely to sleep longer.

In the study, 43 subjects were asked to keep sleep diaries for 105
nights. The researchers crosschecked the diaries with the National
Oceanic and Atmospheric Administration weather database and found that
the higher the barometer—meaning the better the weather—the
more soundly people rested.

The findings explain why people don't want to get up when it's
raining. Researchers add that the sound of rain and lack of sunlight make
it even harder to get out of bed.