It's getting cold out there!

[Velox]

Its too bad the zones don't change with the seasons. Ul'dah is still going to have heat waves in the dead of winter and I'll never see the twelveswood in autumn

Well it's quite possible that Hydaelyn doesn't have seasons because it doesn't have an axial tilt like Earth does (some planets do IRL, such as Mercury and Jupiter which have ~0° axial tilt). In this scenario, primary climate differences globally would be determined strictly by latitude, with secondary climate differences being based on geographic location (altitude, proximity to large body of water, etc.).

A planet without tilt is without seasons