An interesting idea. I hadn't thought about it, but I do have music that I find to be seasonal. Here are my Top-10 winter ones. Next week you might get a different list.

Enya - Shepherd Moon

Jimmy Buffett - You Had To Be There

Bob Marley - Live!

Bruce Springsteen - Nebraska

The Ragbirds - Catch A Fire

Michael McDermott - Ashes

Third World - Reggae Ambassadors

Zachary Richard - Woman In The Room

Emerson, Lake, & Palmer - Brain Salad Surgery

Little Feat - Waiting For Columbus

As you can see when it is cold out, I am heavy on stuff from the Gulf Coast and the Caribbean Islands. Keeps me warm.
 

What a great topic.
Ok here it goes in no particular order.

1. Smile by The Beach boys/Brian Wilson (makes me think of summer)

2. Odessey & Oracle - The Zombies

3. Skylarking -XTC

4. Seven Swans-Sufjan Stevens

5. Michigan-Sufjan Stevens

6. Back to the Egg-Paul McCartney (an ok record but Wonderful Christmastime is on it)

7. Dark Side of the Moon-Pink Floyd

8. Mutations- Beck (ok I'm stealing this one cause its so good.

9 . Sea Change -Beck

10. Lurch -Mike Viola
 

I want to play, I want to play...ok in no order
1. and 2. - duh....Small House and {Stereo} by Brett Mitchell, so eclectic there's a song for every temperature.
3. Beck Odelay
4. Wilco Sky Blue Sky when Brett lets me borrow it
5. Diana Ross - Lady Sings the Blues soundtrack, it's so sultry, though Billie is def better
6. BeeGees - One night Only live recording
7. Emerson, Lake and Palmer - Trilogy
8. Dwight Yoakam's tribute to Porter Wagoner that Donny Brown gave me
9. Blind Faith - I can listen to it in any season, any time, any mood
10. Doors - The Soft Parade, put 50 cents worth of gas in my girlfriend's vw bug and we drove all night long listening to it on her 8 track in 1970
11. America - A Horse With No Name - always makes it seem like summer.
12. Steven Curtis Chapman (my favorite christian lyricist) - The Great Adventure

The Janager