Is it going to rain today?

Meteorology is a horribly inexact discipline, but here’s one aspect you can handle by yourself. In the spring and summer, you sometimes wake up to a completely gray sky. What’s the chance it’s going to rain?
Go outside and look directly up at the sky. Try to decide whether the cloud cover is thin. (You can almost see blue sky through a thin cloud cover. You’ll get the hang of this with a little practice.) If the clouds are thin, the sun is probably boiling them off and you’ll have a blue sky day. If the cloud cover is thick, there’s a good chance of rain.