"The changing of the seasons is still a relatively new concept for IceBeak. She was use to it being cold year-round in her old home, but since she moved, she noticed that there are times where it got cold, and times where it was warm.
Sea Lilly was in a similar boat, having lived in both a tropical environment and the ocean. But after she started exploring Equestria more, she saw the various seasons and was enamored with it. Autumn is one she likes because it isn't too hot or cold, and she loves playing in leaf piles and getting ready for spooky holidays.
Yosh vastly prefers summer and hates the cold, but with it cooling off, he does enjoy a nice cup of hot pumpkin cyder."