Help identify book series from 1980's based on the seasons?
Back when I was a preteen in the 1980s, I remember a scifi/fantasy series with book covers each depicting the different seasons. I think the "spring" one depicted a woman and a man running in a green forest while "autumn?" showed a woman and a man (possibly same couple) riding horses in the forest. The "winter" one depicts humans crossing an icy world.
I think the series dealt with a world where each season lasted a 100 years? It's obviously not George RR Martin's A Song of Ice and Fire. I don't think it's the Helliconia trilogy either (book covers I've found on the internet are not what I remember, unless other versions were made?)
Any one please help? It's been annoying me ever since all the hoopla over GRRM's series began showing on HBO and it jogged my memory of these books - I decided to get them another time but was then unable to ever find them again.