It Started With a Kidnapped Pig...
Weather in the Dessarin Valley
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 (beginning second month of Autumn) to late Tarsakh (halfway into Spring), with temperatures dropping to -30° F / -34.4° C and rarely climbing past 40° F / 4.4° C.
Winters are punctuated by destructive storms howling off the western ocean, dumping 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. Rivers (not the Dessarin River however) freeze over—with ice thick enough to support wagons and draft teams —between Uktar (second half of Autumn) and early Ches (last days of Winter).
Summers in the North are short, but temperatures climb to 80° F / 26.6° C, which —along with high humidity and warm breezes from the south —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.