ELi5: Why does the weather feel much colder when the sun is out with a high UV index in the winter?

Question

ELi5: Why does the weather feel much colder when the sun is out with a high UV index in the winter?

In: 7

Answer 1

Clouds hold in the UV light that passes through them, it kind of bounces around increasing the temperature. On a sunny day the UV just bounces off and goes straight back up.