Does the hottest time of day occur at the same time throughout the year or vary?
Yep, I’ve seen days when the overnight temperature is higher than the midday. That’s because a period of warm weather was interrupted by a cold front. There are lots of conditions that could change where the hottest time of day is. However, assuming the sun is shining all day and there are no big changes in humidity and wind, the hottest time is always an hour or two after the sun reaches highest point in the sky. That is because after midday the sun is still high enough in the sky for a while to continue heating up the surface. So, there is a lag. It is the same reason July is generally hotter than June, even though the sun reaches its highest point in June (in the northern hemisphere).
