Heat — Upper Green River Basin, Wyoming

2025-12-01 to 2025-12-31 · Upper Green River Basin, Wyoming

Event narrative

December was a record warm month at the Big Piney airport. The average temperature of 27.6 degrees was 5.5 degrees higher than the second warmest December. The period of record dates back to 1998.

Wider weather episode

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.

Source: NOAA Storm Events Database, event_id 1307774. Narrative written by the NWS forecast office that issued the report.