Weather in December
lies in the cold winter with the average high temperatures in the 24°F (-4.4°C) to 41°F (5°C) range and the average low temperatures in the freezing 1°F (-17.2°C) to 17°F (-8.3°C) range across the state. The eastern portion of Wyoming
is comparatively milder with high temperatures in the 35°F (1.7°C) to 41°F (5°C) and low temperatures above 10°F (-12.2°C), while the western and northern areas frequently see nights drop well below 10°F (-12.2°C).
Rain is negligible in most parts of the state as only a few places like Old Faithful in Yellowstone National Park register a meaningful 3.2" (81mm).
Snowfall is heavy in the northwest part of the state, such as Moose, which records 44" (1118mm), while the rest of the lowlands register 10" (254mm) to 15" (381mm).
December usually wears a blanket of snow around the state as a few tourists brave the cold to enjoy activities like snowmobiling, snowshoeing, cross-country skiing, snow tubing, among others - take care to wear layers of warm clothing before engaging in outdoor activities.