Rain => Sleep

Empirical Observation: I tend to sleep-in (or oversleep my alarm) on mornings when it's raining; my state of sleep is also deeper.

In fact, if I oversleep my alarm, I can often successfully predict that in fact it is raining outside. This is the usual cause. "Oh, crap, I overslept...well, let's take a look outside the window...and yeah, it's raining." Case in point was this morning. Well, yes, you can't really oversleep on a Sunday, it's sorta the point not to get up early. But it was later than I wanted to get up.

This has been something I've noticed since high school; how many a rainy morning caused a tardy entrance to first period? Of course, in commutation with the rushed start, you're wet walking into school, grumpy because being late you couldn't find a good parking space. It's the start of a sucky day.

Maybe it's all in my head - just a coincidence I mentally invented. Or maybe there is something there. I'll have to poll others regarding this. But there has to be a deeper root cause than just the precipitation itself; it's not like the raindrops ferry tiny sleep pixies to my bedroom. Could it be something to do with the low pressure that accompanies storms? Rainclouds making the mornings darker? Raindrops continuing to soothe me asleep as track number 19 of the easy listening CD selling at Bed Bath and Beyond?