The majority of the North, including the islands and the Spine of the World, fall in a subarctic clime. Long, bitter winters typically last from mid Marpenoth to late Tarsakh, with temperatures dropping to -30° F and rarely climbing past 40° F. Winters are punctuated by destructive storms howling off the westem ocean, dumping mixed snow and rain on the coastline and heavy snow across the mountains and midlands. Frequent blizzards blanket the land in snow drifts (often 10 feet deep) that isolate communities from one another. In the mountains, temperatures approach arctic iciness, while the forests shrug off the worst effects of winter (some woods, like Neverwinter Wood and the southern High Forest, never feel winter at all). Rivers freeze over with ice thick enough to support wagons and draft teams - between Uktar and early Ches.
Summers in the North are short, but temperatures climb to 80° F, which - along with high humidity and warm breezes from the southern seas keeps it warm enough for most anyone (if not uncomfortable at times). Precipitation normally takes the form of rain, but hail, sleet, and snow are common. Summer is the time for wizard weather, when unpredictable - even magical weather patterns occur in the vicinity of the High Forest.
The cloud cover over the North seems eternal and unbroken. Partially sunny days are common, but a day without clouds in the North is difficult to conceive and usually worth noting.