Originally Posted by LunaZ

Generally, a rain race brings out the best (or worst) in a driver and their car.
Traction is pushed to the limit, and pit and tyre strategies become more important. Especially at a large track like Spa-Francorchamps where it may be dry on one end of the track, but raining at the other.
The resulting drama makes for a lot of tense moments which make those races fun to watch.