This is different from weather effect, which would probably take forever unless RR3 turns iOS-exclusive.
Fo some tracks, especially the mountain ones, it would be nice if the scenery change according to season. Imagine running the SPA track with fall foliage and yellow grass around you! That's should be an easy change, and EA should be able to just change some existing races to autumn season. The scenery changes but the racing doesn't.
For winter and spring, that may be more tricky. It would be unnatural if the surrounding is all white but the track is all clean. It would be more realistic if we lose some grip. However, it would not be an easy task adding tracks to existing series.
For spring, I would imagine some fog. Rendering wouldn't be easy, and the Le Mans track might just crash many Android phones.