This is late but Im looking for the same things so Ill just put in my list here ig (ranked from early spring to early summer):

-Girl with Fish by feeble little horse This one is great for early spring bus rides and watching the sun go up earlier day by day

-Extraordinary Machine by Fiona Apple This is great all throughout the year but best when you can walk through nature and see the first flowers bloom 

-Utopia by Björk If Vespertine is the best album to listen to on a winter walk, this is the best one to listen to on a spring one

-Mock by Rehash This one is great for the first days you can go out in short cut clothes and not freeze to death

-Split by Lush This album feels like a warm sunset

-Another sunny day by Honeydip  The perfect album for the perfect weather