Much to the chagrin of the wifey whenever it rains I have a certain music playlist I like to play, but there’s only a few songs on there, more needs to be added.
So far I have:
“Raining on Sunday” Keith Urban
“Songs About Rain” Gary Allen
“Come Clean” Hilary Duff
“Is it Raining Where You Are?” Brad Paisley
“Purple Rain” Prince
That’s all I have so far.
“I’m Only Happy When It Rains” - Garbage
even as a hetero male, lots of norah jones
Led Zeppelin - The Rain Song
The Doors - Riders on the Storm
The Beatles - Rain
Stevie Ray Vaughan - Texas Flood
The Weather Girls’ “It’s Raining Men”? 
“I Can’t Stand the Rain” - I like the version off the soundtrack of The Commitments.
“It’s Raining” – Rick Derringer
“Red Rain”, “Here Comes The Flood” – Peter Gabriel
Rhythm of the Rain – Cascades
Summer Rain – Johnny Rivers
The Rain, the Park & Other Things – Cowsills
Let It Rain – Eric Clapton
In the Rain – Dramatics
Raining in My Heart – Buddy Holly
Who’ll Stop the Rain – Creedence Clearwater Revival
Love, Reign O’er Me – Who
Candles in the Rain - Melanie
A Little Fall of Rain from Les Miserables. Also recroded in about 20 other languages.
The Association - Windy
Dennis Yost - Stormy
Willie Nelson - Blue Eyes Crying In The Rain
“Here Comes the Rain Again” by Eurythmics
“Blame It On the Rain” by session musicians, but credited to Milli Vanilli
“When the Rain Comes” by the Beatles
“Cold Rain and Snow” by the Grateful Dead
“Ball and Chain” (lyrics - “Sitting by my window, looking out at the rain…”) by either Janis Joplin or ‘Big Mama’ Thornton
“Red Rain” - Peter Gabriel
I was going to suggest both Led Zeppelin’s “Rain Song” and SRV’s “Texas Flood” but it looks like those were rather popular, so how about:
Stevie Ray Vaughan “The Sky is Crying”
The Who - “Love Reign O’er me”
Led Zeppelin - “When the Levee Breaks”
What? 
Violent Femmes - “I Hear the Rain”
Gotta kill the pain.
“Bring On the Rain” by Jo Dee Messina
Supertramp: “It’s Raining Again”
Madness: “The Sun and the Rain”; “In the Rain”
Rainy Day Women #12 & 35 - Bob Dylan
Rainy Day People - Gordon Lightfoot
Early Morning Rain - Peter, Paul and Mary
Warrant - Mr. Rainmaker
Brad Paisley - Rainin’ You
Chris LeDoux - Between the Rainbows and the Rain
“Colored Rain” – Traffic
“Walking in the Rain” – Flash and the Pan
“Saddle in the Rain” – John Prine
“Rain on the Roof” – Lovin’ Spoonful
"Isn’t a Lovely Day (to be Caught in the Rain) – Fred Astaire
“Rain” – Kak
Georgia Rain - Trisha Yearwood
Like the Rain - Clint Black
Rain - The Wreckers
Paper Rain - Amanda Stott
I refused to add any more different songs titled ‘Let it Rain’
Ooh, I forgot these:
“Rain King” by Counting Crows
“November Rain” by Guns N Roses
“She’s My Kind of Rain” by Tim McGraw
“Rain” by Breaking Benjamin
“No Rain” by Blind Melon
B.J. Thomas - Raindrops Keep Fallin’ On My Head
Neil Young - Like a Hurricane