Frost dates · Wyoming
Wyoming frost dates, county by county.
Last spring frost and first fall frost probability data for all 23 counties in Wyoming, computed from the NOAA 1991–2020 Climate Normals. Every county page surfaces the full probability table at three temperature thresholds plus crop-specific planting guidance.
Variation across Wyoming
43 days separate the earliest and latest counties.
The median last spring frost in Hot Springs County is April 23 — 43 days earlier than Sublette County at June 5. Statewide averages aren't useful planting tools; pick your county below for the data that actually applies to your fields.
By geography
Wyoming counties on the map.
Each polygon is a county. Click for full frost-date detail. Color shows last-spring-frost timing — sage = earliest, amber = latest.
MapList
Last spring frostEarliestMedianLatest
23 counties · click any county for full frost data