eli5: Why does the temperature start dropping before sunset?

Question

I always thought that once the sun set the temperature started to drop, but today I noticed it started to cool down 2 hours before the sunset. Why is that?

In: 5

Answer 1

See the [graphs here](https://www.sciencedirect.com/science/article/pii/S2405844018388352#fig2) to see how light and heat from the sun varies over 24 hours. Notice that the sun doesn’t simply turn on at dawn and off at dusk; its heat increases and decreases gradually due to a number of effects discussed in the article.

Mostly the reason is that the sun, when near the horizon, shines across the land and so relatively little hits the land to heat it up. It’s also more likely to hit clouds when near the horizon.