Not only have I seen 'Hints' in game about seasons but on some social media such as Twitter and Facebook, saying that seasons is being worked on.. YAY can't wait, but I have a feeling that it won't co...
It would probably work like the festivals, like someone pointed out earlier. The bigger change would be how temperatures and precipitation would affect the Sims' moods and such. I could see Sims getting that sad face and a poor moodlet from getting soaked (like with the Toddler interaction) or overheated (like the fatigued moodlet after working out too much). Maybe Hygiene could also drop faster in summer...?