Frost dates · Colorado
Colorado frost dates, county by county.
Last spring frost and first fall frost probability data for all 64 counties in Colorado, 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 Colorado
75 days separate the earliest and latest counties.
The median last spring frost in Mesa County is April 8 — 75 days earlier than San Juan County at June 22. Statewide averages aren't useful planting tools; pick your county below for the data that actually applies to your fields.
By geography
Colorado 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
64 counties · click any county for full frost data