My trees are dormant in mild temperatures? (Answered)

That's okay; I'm not fussed about the holidays @igazor . I've created thirteen of my own anyway - just for my sims to celebrate, not by modding the game or anything. They're very much centered around the agricultural year, which is why the dormant trees were such a nasty surprise, but if I lengthen my summer I can move some of the autumn ones there. I'll just have to do some maths (boo) to work out what days they should fall on, and also change my Tempest settings.

Thanks again for the info.