Correlation of Sleep with Temperature and Seasons

[Jay Aitchsee]

Below are charts which depict the correlation between two variables: Average Percentage of Deep Sleep and Average High Outside Temperature. The Average Percentage of Deep Sleep is derived from my Zeo data of July 2011 into January 2013. It is the result of the daily amount of deep sleep divided by the daily total Z, smoothed by a 15 day moving average. The Average High Outside Temperature is provided by my electric company at FPL.com. For the months prior to October 2012, the Average High Temperature is the monthly average high temperature as reported by FPL. For the months October through December, it is the daily high temperature as reported by FPL, smoothed by a 15 day moving average. Note the Y axis for AVG High Temperature is reversed.

The charts are an outgrowth of the work depicted in my previous thread: Charting Rescan and Zeo, which hinted there may be a seasonal aspect to my deep sleep. But this result was so surprising with such a high degree of correlation, that I thought it deserved a new thread. I don't think my deep sleep is directly related to the outside temperature since the house is air conditioned, but it's possible my deep sleep is indirectly related to the outside temperature, through another means such as the air conditioning.

What do you think? Any theories?



Edited to change title of thread

[RestedRebel]

Just speaking for myself, I know that I sleep better when the temperature is cool or cold at night, or when I have my A/C on low at night. I usually put my A/C down at night in the summer and then adjust it much higher during the day. Now that it's winter and cold outside at night, I'm sleeping quite well. I've also read in magazines that temperatures in the high 60s at night in the bedroom are ideal for sleep - for all people.

[chunkyfrog]

Maybe it's the security of the blanket and quilt cocoon
I have to snuggle into just to avoid freezing my off.
In any case, turning the heat up makes it less traumatic to get out of bed.

[MaxDarkside]

Probably goes back deep into our genetics re: hibernation during Winter

[MaxDarkside]

I also see in the more detailed recent data that there may be a leading of Deep vs. Temp, which may suggest you're sensitive to something changing (barometric pressure?). (yer a weather gauge!)

[Always tired]

Jay,
Possibly less A/C in the winter months could increase or decrease humidity in your house? Less A/C in general? Is your winter a wet season? Seasonal diet changes around Thanksgiving and Christmas for instance more L-tryptophan? Better mental attitude around the Holidays?
A T

[quietmorning]

Wow. I may start using my zeo again to see if I might do better in my cold room sleep wise. I quit using it because it seemed no matter what I did, I got fifteen minutes of deep sleep a night. Period. Or less. . .but never more.

[Jay Aitchsee]

Jay,
Possibly less A/C in the winter months could increase or decrease humidity in your house? Less A/C in general? Is your winter a wet season? Seasonal diet changes around Thanksgiving and Christmas for instance more L-tryptophan? Better mental attitude around the Holidays?
A T

All possibilities, AT. The seasonal diet thing is interesting. Winter is our dry season, when we would experience the absolute lowest humidy, at other times (summer), humidity is controlled with AC.
The electric company site, now that we have "smart meters", does provide quite a bit of information; Hight Temps, Low Temps, Humidities, Peak and Off Hours, etc., could be some other clues there.

Probably goes back deep into our genetics re: hibernation during Winter

Ya' know, Max, there could be something to this.

Just speaking for myself, I know that I sleep better when the temperature is cool or cold at night, or when I have my A/C on low at night. I usually put my A/C down at night in the summer and then adjust it much higher during the day. Now that it's winter and cold outside at night, I'm sleeping quite well. I've also read in magazines that temperatures in the high 60s at night in the bedroom are ideal for sleep - for all people.

I know that's true, Rebel. I don't know how much my bedroom temperature varies at night. In the summer, the AC's on, in the winter if it gets much below 60, we in florida are going to turn on the heat.
I'm going to have to get one of those recording thermometers, I guess.

[old64mb]

I vaguely remember reading a journal piece on ideal temperature and sleep quality a while back that didn't really do much for me, but my thought would be that you'd need a couple more variables to really bore down on this. If it were me, I'd look at sunlight exposure (both total and morning exposure) and outdoor physical activity as two more independent variables that can vary dramatically in winter time.

[TheUglyTruth]

Max: I also see in the more detailed recent data that there may be a leading of Deep vs. Temp, which may suggest you're sensitive to something changing (barometric pressure?).

I sleep better when it is cold in the bedroom. And this is better when the bedroom temperature is driven down by outside cold instead of A/C.

I sleep better during times of high barometric pressure.

Wonder why?

[patrissimo]

Wow, that's an amazingly strong relationship. I'd expect more sleep in the winter based on light cues / circadian rhythms.

[SethW]

What do you think? Any theories?

If I remember correctly, my deep sleep usually gets knocked out in the first few hours of sleeping, so my % of deep sleep would be lower on days I could sleep in because I only got (at most) a few hours of deep sleep no matter how long I slept. I would get a nice high total Z score on those days, though.

I think you should probably see if there is any correlation after taking into account the total amount of sleep you get. You might perhaps be measuring a correlation between the time of the year and how much sleep you get. For me, a higher % in winter and a lower % in summer would mean I was sleeping in during the summer. You're not going to college right now, are you?

[johnthomasmacdonald]

I had a good friend who when he couldn't sleep he would turn the AC up way high in his bedroom ( or leave the window open in the winter) and then take a hot bath - very hot - as hot as he could stand it - then he would run back into the bedroom, close the window and hop into bed - he claimed it pretty much knocked him out unconscious so fast he could barely close the window

I never tried it since i never had sleep problems and i never thought of it again prior to your post - now that i have sleep problems, i'll give this a try

I used to do a lot of winter camping by the way - in snow and i don't remember sleeping particularly well - quite the opposite actually

[noeldoku]

Haven't had time to read all the comments but just from eye-balling it looks like the scatter-plot data could be clustered: one top left and another bottom right. This might come about if you are switching between two activities that have a significant impact on your sleep - if you're more likely to engage in one activity on days with higher temperature then you could see an incidental correlation between temperature and quality of sleep. Try categorising the data into groups and comparing your activities, you might find a simple factor differentiates them.

Presuming that there are groups/clumps within the data then it'd be interesting to determine the conditional correlation (the correlation within each group) to check if the 2 variables are still related once you factor out whatever might be causing the data to clump.

Don't know if this helps, but thought I'd throw it in the mix!

[JamesW6175]

First , I would question your temperature readings. Reason - first you are sleeping at night, so you can't count the daytime temperatures. It would throw your counts off, and I am thinking that the humidity varies more at night, than in the day since it would be cooler. If I am wrong, I am sorry.