I have a current ticket on the matter. Here is their "explanation""
Hello Mayor, thank you for contacting us.
I see you are concerned because there is no snow over the mountainside buildings in the Frosty Fjords region and snow appeared in different region though. It can be annoying to see such issue in the game. Allow me to explain the issue further.
With very recent game update it seems new feature has been introduced like climate change. I do believe after sometime you will start seeing the snow everywhere in the individual region. Sometime you will see the greenery only rather than seeing snow.
Attached screenshot states that few buildings has snow because those buildings are inbuilt with snow and were earned during winter season or events.
However, we'll make sure to forward the information to the game team for further checking and possible changes which should not bother our players during game play.
Hope I was able to clear the confusion and help you out.
Please feel free to contact us again if you need further assistance in game. Thanks!
I could accept that as an answer if there was some consistency to the buildings, but I have "Green" ones in the white area, and white ones in the green area now. Ugly!!
Aldebera