I have some Winnie the Pooh books where the seasons have been changed so they are appropriate for the Southern Hemisphere, I think they were Reader's Digest books (my Grandma bought them for DS1). They are very clear seasons though, snow for winter, orange leaves falling in Autumn... so we have still had to talk about how our seasons here in QLD aren't as clear cut. You would probably find something if you searched online, but I don't think it matters too much. Just talk about how and why it is different here to in the book you are reading.