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
886 days separate the earliest and latest counties.
The median last spring frost in Hot Springs County is April 23 — 886 days earlier than Teton County at —. Statewide averages aren't useful planting tools; pick your county below for the data that actually applies to your fields.
By frost timing
Counties sorted by last spring frost.
Latest at top, earliest at bottom. In most states this matches the north-to-south gradient.
- Teton CountySpring —·Fall —0-day season
- Sublette CountySpring Jun 5·Fall Sep 491-day season
- Uinta CountySpring May 30·Fall Sep 20113-day season
- Lincoln CountySpring May 24·Fall Sep 15114-day season
- Carbon CountySpring May 17·Fall Sep 26132-day season
- Park CountySpring May 11·Fall Oct 5147-day season
- Natrona CountySpring May 10·Fall Oct 1144-day season
- Goshen CountySpring May 9·Fall Oct 1145-day season
- Laramie CountySpring May 9·Fall Oct 1145-day season
- Platte CountySpring May 9·Fall Oct 1145-day season
- Weston CountySpring May 9·Fall Oct 2146-day season
- Converse CountySpring May 8·Fall Oct 1146-day season
- Johnson CountySpring May 8·Fall Sep 30145-day season
- Albany CountySpring May 7·Fall Oct 4150-day season
- Sheridan CountySpring May 7·Fall Oct 3149-day season
- Sweetwater CountySpring May 7·Fall Oct 5151-day season
- Crook CountySpring May 6·Fall Oct 3150-day season
- Niobrara CountySpring May 5·Fall Oct 5153-day season
- Fremont CountySpring May 3·Fall Oct 7157-day season
- Big Horn CountySpring May 2·Fall Oct 3154-day season
- Campbell CountySpring May 2·Fall Oct 10161-day season
- Washakie CountySpring May 1·Fall Oct 5157-day season
- Hot Springs CountySpring Apr 23·Fall Oct 15175-day season
Alphabetical
All Wyoming counties — A to Z.
- Albany County
- Big Horn County
- Campbell County
- Carbon County
- Converse County
- Crook County
- Fremont County
- Goshen County
- Hot Springs County
- Johnson County
- Laramie County
- Lincoln County
- Natrona County
- Niobrara County
- Park County
- Platte County
- Sheridan County
- Sublette County
- Sweetwater County
- Teton County
- Uinta County
- Washakie County
- Weston County