# Coldest months of the year? **URL:** \ **Category:** Factual Questions\ **Created:** [December 18, 2002, 3:35pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564 "2002-12-18T15:35:06Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Swampwolf](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Swampwolf](https://boards.straightdope.com/u/Swampwolf)\ **Post date:** [December 18, 2002, 3:35pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/1 "2002-12-18T15:35:06Z")
Why is it that January and February are the coldest months of the year (in the Northern Hemisphere, that is)? At the Winter Solstice, the days start getting longer. More sunlight/increased surface area exposed to the sun should make things warmer. Also, according to the sites I googled, Jan. and Feb. are not when the Earth is farthest from the sun (which wouldn’t really matter anyway, because the Summer in the Southern Hem. is the same, temperature-wise as in the Northern Hem.). So…what gives? ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [December 18, 2002, 3:48pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/2 "2002-12-18T15:48:24Z")
Just a WAG, but my guess is that the coldest months are determined by weather patterns… not just the absolute distance you are from the Sun. That is, the cold weather usually comes from somewhere else, like Canada for example, and the air masses pushing that cold air down on the US are more prevalent in Jan/Feb than Dec for some reason. Perhaps it takes a month or two of really cold weather somewhere else before it reaches you. Again, IANAMetorlogist… but I expect one will be coming by shortly. ---
**Author:** ![Rayne\_Man](https://avatars.discourse-cdn.com/v4/letter/r/df705f/32.png) [@Rayne\_Man](https://boards.straightdope.com/u/Rayne_Man)\ **Post date:** [December 18, 2002, 5:06pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/3 "2002-12-18T17:06:16Z")
For somewhere like the UK this is determined by the temperature of the surrounding seas. These bodies of water take time to cool down from the summer highs and act as a heat reserve. It is only in January to March , when the water as cooled down , that we get the coldest temperatures. For example we have just had a cold snap. We had winds from the east blowing off a very cold continent ( daytime Moscow was - 15c ) but because the North Sea is still relatively warm the coldest temperatures we had we had were just below freezing. ---
**Author:** ![Engywook](https://avatars.discourse-cdn.com/v4/letter/e/bc8723/32.png) [@Engywook](https://boards.straightdope.com/u/Engywook)\ **Post date:** [December 18, 2002, 5:28pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/4 "2002-12-18T17:28:27Z")
For larger continents, though, I had a theory that there’s more of those cold north (or south) winds because of sunlight. As the days start to get longer, some parts of the world that have been in the dark for a while get sun again. The sun gets all that cold air unsettled, so there are stronger air currents from around the poles. Like I said, just a WAG… maybe Rayne Man’s ocean explanation accounts for the awfulness of Jan - Mar even if you’re nowhere near the water. ---
**Author:** ![Reeder](https://avatars.discourse-cdn.com/v4/letter/r/c6cbf5/32.png) [@Reeder](https://boards.straightdope.com/u/Reeder)\ **Post date:** [December 18, 2002, 5:45pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/5 "2002-12-18T17:45:38Z")
It’s not the distance from the sun but the angle of the earth when sunlight hits it. In the northern hemisphere during the winter, the earth is angled back so the sunlight glances off. ---
**Author:** ![Swampwolf](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Swampwolf](https://boards.straightdope.com/u/Swampwolf)\ **Post date:** [December 18, 2002, 6:05pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/6 "2002-12-18T18:05:44Z")
Thanks for the answers people! The water temp thing sounds about right to me. I didn’t think of checking that, but I’ll look into it later on. > [@](#): > > \*Originally posted by Reeder \* > \*\*It’s not the distance from the sun but the angle of the earth when sunlight hits it. In the northern hemisphere during the winter, the earth is angled back so the sunlight glances off. \*\* It can’t be that, because after the solstice, the angle changes so that more sunlight hits the northern hemisphere. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [December 18, 2002, 6:06pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/7 "2002-12-18T18:06:13Z")
Both land and water take time to heat up and time to cool down and that explains the lag. And yes, the planet Earth is at its perigee (closest to the Sun) about January 3 but the difference in distance is very small and that has no practical effect on the seasons or the weather. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [December 18, 2002, 6:07pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/8 "2002-12-18T18:07:08Z")
I am not a meteorologist but I think this is what happens. When the solstice passes, even through the rays are become more direct and days longer, heat is lost at a rate that is still faster than the gain from the sun’s radiation. It takes a while to catch up. Same logic applies in reverse as to why it’s so hot in August several weeks after the summer solstice has passed. BTW if a meteorologist is someone who studies weather, what do you call someone who studies meteors? ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [December 18, 2002, 7:24pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/9 "2002-12-18T19:24:30Z")
[The Master has spoken.](http://www.straightdope.com/classics/a1_170b.html) (Well, that’s all I found searching the archives. It’s just down a ways.) ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 18, 2002, 9:46pm UTC](https://boards.straightdope.com/t/coldest-months-of-the-year/143564/10 "2002-12-18T21:46:11Z")
I believe the effect is called _hysteresis_; the effect lags behind the cause (it couldn’t very well precede it).