# Why is the middle of winter the coldest? **URL:** \ **Category:** Factual Questions\ **Created:** [March 10, 2009, 2:28am UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911 "2009-03-10T02:28:45Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![snailboy](https://avatars.discourse-cdn.com/v4/letter/s/97f17d/32.png) [@snailboy](https://boards.straightdope.com/u/snailboy)\ **Post date:** [March 10, 2009, 2:28am UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/1 "2009-03-10T02:28:45Z")
Winter solstice, the shortest day in a hemisphere, is at the beginning of winter in late December. Since that’s when there’s the least sunlight, that’s when you’d expect the coldest days. Yet January and early February tend to be colder. Why is this? Does it simply take a while for Earth’s temperature to catch up with the amount of sunlight it’s receiving due to its heat capacity? ---
**Author:** ![IdahoMauleMan](https://avatars.discourse-cdn.com/v4/letter/i/71c47a/32.png) [@IdahoMauleMan](https://boards.straightdope.com/u/IdahoMauleMan)\ **Post date:** [March 10, 2009, 2:33am UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/2 "2009-03-10T02:33:00Z")
> [@snailboy](#): > > Winter solstice, the shortest day in a hemisphere, is at the beginning of winter in late December. Since that’s when there’s the least sunlight, that’s when you’d expect the coldest days. Yet January and early February tend to be colder. Why is this? Does it simply take a while for Earth’s temperature to catch up with the amount of sunlight it’s receiving due to its heat capacity? Yes. ---
**Author:** ![snailboy](https://avatars.discourse-cdn.com/v4/letter/s/97f17d/32.png) [@snailboy](https://boards.straightdope.com/u/snailboy)\ **Post date:** [March 10, 2009, 2:44am UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/3 "2009-03-10T02:44:05Z")
10-4. That was a quick and easy answer. I’m going to have to start coming up with harder questions. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 10, 2009, 2:50am UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/4 "2009-03-10T02:50:49Z")
Which is basically the same answer as to the question we had the other day about it getting colder at dawn. ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [March 10, 2009, 7:47am UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/5 "2009-03-10T07:47:14Z")
Since the original question has been answered…hijack. If the daily teperatures were charted, beginning of winter to the end, would they form a bell curve? ---
**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:** [March 10, 2009, 12:41pm UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/6 "2009-03-10T12:41:57Z")
> [@bobo t](#): > > If the daily teperatures were charted, beginning of winter to the end, would they form a bell curve? The term “bell curve” means something pretty specific in statistics with regard to frequency distribution. That’s not the same thing as charting temperatures over time. My guess (I couldn’t find any actual data after a few minutes of searching) would be that a chart of temperatures would be close to a sine curve, which is roughly similar to a bell curve but not mathematically the same. ---
**Author:** ![K364](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k364/32/5_2.png) [@K364](https://boards.straightdope.com/u/K364)\ **Post date:** [March 10, 2009, 12:42pm UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/7 "2009-03-10T12:42:55Z")
So, when is the middle of winter? Second week of January? ---
**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:** [March 10, 2009, 12:52pm UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/8 "2009-03-10T12:52:16Z")
> [@K364](#): > > So, when is the middle of winter? > > Second week of January? In the northern hemisphere the middle of winter is around Feb 5. Halfway between 12/21 and 3/20. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [March 10, 2009, 4:06pm UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/9 "2009-03-10T16:06:03Z")
It’s also worth noting that the identification of the solstices with the beginning of seasons seems to be a uniquely [North American phenomenon](http://www.straightdope.com/columns/read/161/is-it-true-summer-in-ireland-starts-may-1). So it depends on your definition of “middle.” 🙂 ---
**Author:** ![A\_Dodgy\_Dude](https://avatars.discourse-cdn.com/v4/letter/a/a87d85/32.png) [@A\_Dodgy\_Dude](https://boards.straightdope.com/u/A_Dodgy_Dude)\ **Post date:** [March 10, 2009, 8:37pm UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/10 "2009-03-10T20:37:50Z")
I don’t know if this helps the conversation any, but here goes: In NYC, the absolute dead of winter is January 21-25. On those five days, the average temp is the lowest it gets for the entire year … 31.5 degrees as I recall. ---
**Author:** ![Annie-Xmas](https://avatars.discourse-cdn.com/v4/letter/a/ecc23a/32.png) [@Annie-Xmas](https://boards.straightdope.com/u/Annie-Xmas)\ **Post date:** [March 10, 2009, 8:42pm UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/11 "2009-03-10T20:42:08Z")
As the days lengthen The cold does strengthen The days grow longer The cold grows stronger Both Old New England sayings ---
**Author:** ![snailboy](https://avatars.discourse-cdn.com/v4/letter/s/97f17d/32.png) [@snailboy](https://boards.straightdope.com/u/snailboy)\ **Post date:** [March 10, 2009, 8:49pm UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/12 "2009-03-10T20:49:12Z")
> [@friedo](#): > > It’s also worth noting that the identification of the solstices with the beginning of seasons seems to be a uniquely [North American phenomenon](http://www.straightdope.com/columns/read/161/is-it-true-summer-in-ireland-starts-may-1). > > So it depends on your definition of “middle.” 🙂 Very interesting. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [March 10, 2009, 8:57pm UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/13 "2009-03-10T20:57:08Z")
> [@CookingWithGas](#): > > In the northern hemisphere the middle of winter is around Feb 5. Halfway between 12/21 and 3/20. The old “cross-quarter days” beloved of Neopagans were originally the halfway points through the seasons: Imbolg (Candlemas, Groundhog Day) - Feb. 2; Samhain (All Saints, Hallowe’en) - Oct. 31-Nov. 1; May Day, May 1; and Lammas, in early August. ---
**Author:** ![K364](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k364/32/5_2.png) [@K364](https://boards.straightdope.com/u/K364)\ **Post date:** [March 11, 2009, 3:35am UTC](https://boards.straightdope.com/t/why-is-the-middle-of-winter-the-coldest/488911/14 "2009-03-11T03:35:26Z")
> [@CookingWithGas](#): > > In the northern hemisphere the middle of winter is around Feb 5. Halfway between 12/21 and 3/20. To clarify what I meant was… Statistically, when is the cold of winter likely to bottom out? As A Dodgy Dude explained for NYC. Likely to vary a bit by region I guess.