Summer And Winter Temperatures In All The Regions

Never seen this discussion before. What do you think the average summer and winter temperatures would be for all the Pokemon regions? This includes the orange islands as well. I think that the Alola region would be the hottest and Sinnoh the coldest with Snowpoint City. You could even include Orre if that counts.

Alola and Hoenn just because they're both tropical based regions which generally are associated with heat. Coldest I'd go for Sinnoh just due to Mt. Coronet splitting the region which would make you think that one half would miss out on a lot of sunlight at certain times of the year.