Maybe I did not pay enough attention during class? But surely the shortest day, is also the coldest day? And then after the coldest day, we start moving back towards the warmest day again.



It would only be true if there were no storage effects:


  • If the measured temperature represented everything that affected the temperature. It does not: air temperature does not cover ground temperature. In practice, as others have pointed out, the temperature is moderated by the energy stored in the ground and surface water.
  • If the point of minimum energy input equated to the point of lowest temperature. It doesn't. Nor does the point of maximum input equate to the point with the highest temperature. You can observe this at home heating or cooling a pot of water.

There are many articles explaining this, e.g. https://www.insidescience.org/news/solstice-shmolstice-%E2%80%93-why-coldest-days-are-still-come



Thats a great explanation. Thank you.