Might as well make the best of it, because here it comes again.
Here are some songs that talk about rain; some of which I like, some of which just get stuck in my head when it's raining, some of which I never heard until I started searching for rain songs.
Eurythmics: Here Comes the Rain Again
personal note: I saw Annie Lennox sing this live, while it was raining.
BJ Thomas: Raindrops Keep Falling on my Head (I saw BJ Thomas sing this, but it was not raining.)
Creedence Clearwater Revival: Have You Ever Seen the Rain and Who'll Stop the Rain (thanks Leah)
Rihanna: The Umbrella Song Not really my musical preference, but it's definitely a rain song.
The Beatles: Rain (with some sunshine, too)
Clint Black: Like the Rain
Tom Waits: More than Rain
Carpenters: Rainy Days and Mondays (wish I had vid. for the Cracker remake)
There's a million more. Purple Rain, I'm Only Happy When it Rains. Rain seems to be a good topic for music. Snow doesn't seem to have as wide a reach. Lots of sunshine songs though. If I ever see the sun for 12 hours straight again, maybe I'll post those next.