Heat in Yellowstone National Park, Wyoming

Lake Yellowstone had a record warm average temperature of 23.2 degrees, breaking the old record of 20.6 degrees in 2024. The period of record dates back to 1998.

Persistent ridging across the northern Rockies brought record warmth to western and central Wyoming for December. Many airports with a 20 to 30 or more year period of record had the warmest December on record. Most sites were at least 10 degrees above normal for the month, with Riverton running more than 15 degrees above normal. Numerous high temperature records were set throughout the month.