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
901 days separate the earliest and latest counties.
The median last spring frost in Mesa County is April 8 — 901 days earlier than Jackson 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.
- Jackson CountySpring —·Fall —0-day season
- San Juan CountySpring Jun 22·Fall Sep 979-day season
- Summit CountySpring Jun 18·Fall Sep 680-day season
- Park CountySpring Jun 15·Fall Sep 885-day season
- Lake CountySpring Jun 12·Fall Sep 1090-day season
- Mineral CountySpring Jun 11·Fall Sep 1394-day season
- Larimer CountySpring Jun 6·Fall Sep 14100-day season
- Boulder CountySpring Jun 4·Fall Sep 14102-day season
- Gunnison CountySpring Jun 4·Fall Sep 17105-day season
- Moffat CountySpring Jun 1·Fall Sep 19110-day season
- Eagle CountySpring May 31·Fall Sep 21113-day season
- Hinsdale CountySpring May 31·Fall Sep 23115-day season
- Rio Grande CountySpring May 30·Fall Sep 23116-day season
- Custer CountySpring May 28·Fall Sep 20115-day season
- Grand CountySpring May 26·Fall Sep 20117-day season
- Ouray CountySpring May 26·Fall Sep 23120-day season
- Archuleta CountySpring May 23·Fall Sep 30130-day season
- Gilpin CountySpring May 21·Fall Sep 26128-day season
- Rio Blanco CountySpring May 21·Fall Sep 27129-day season
- Routt CountySpring May 20·Fall Sep 23126-day season
- Alamosa CountySpring May 16·Fall Sep 27134-day season
- Chaffee CountySpring May 15·Fall Oct 2140-day season
- Clear Creek CountySpring May 15·Fall Sep 30138-day season
- Teller CountySpring May 14·Fall Oct 4143-day season
- Conejos CountySpring May 13·Fall Sep 29139-day season
- Costilla CountySpring May 13·Fall Sep 30140-day season
- Pitkin CountySpring May 13·Fall Oct 2142-day season
- Montrose CountySpring May 11·Fall Oct 8150-day season
- San Miguel CountySpring May 11·Fall Oct 8150-day season
- Garfield CountySpring May 9·Fall Oct 4148-day season
- Jefferson CountySpring May 9·Fall Oct 2146-day season
- La Plata CountySpring May 7·Fall Oct 12158-day season
- Saguache CountySpring May 4·Fall Oct 8157-day season
- Weld CountySpring May 3·Fall Oct 5155-day season
- Adams CountySpring May 2·Fall Oct 10161-day season
- Arapahoe CountySpring May 2·Fall Oct 10161-day season
- Dolores CountySpring May 2·Fall Oct 19170-day season
- Elbert CountySpring May 2·Fall Oct 11162-day season
- Douglas CountySpring May 1·Fall Oct 12164-day season
- Lincoln CountySpring May 1·Fall Oct 10162-day season
- Phillips CountySpring May 1·Fall Oct 12164-day season
- Montezuma CountySpring Apr 30·Fall Oct 17170-day season
- Washington CountySpring Apr 30·Fall Oct 15168-day season
- Huerfano CountySpring Apr 29·Fall Oct 15169-day season
- Otero CountySpring Apr 29·Fall Oct 11165-day season
- Yuma CountySpring Apr 29·Fall Oct 15169-day season
- Cheyenne CountySpring Apr 28·Fall Oct 14169-day season
- Kit Carson CountySpring Apr 27·Fall Oct 19175-day season
- Morgan CountySpring Apr 27·Fall Oct 15171-day season
- Sedgwick CountySpring Apr 27·Fall Oct 16172-day season
- Fremont CountySpring Apr 26·Fall Oct 17174-day season
- Delta CountySpring Apr 25·Fall Oct 19177-day season
- Baca CountySpring Apr 24·Fall Oct 19178-day season
- El Paso CountySpring Apr 24·Fall Oct 16175-day season
- Crowley CountySpring Apr 23·Fall Oct 16176-day season
- Las Animas CountySpring Apr 23·Fall Oct 18178-day season
- Denver CountySpring Apr 22·Fall Oct 18179-day season
- Prowers CountySpring Apr 21·Fall Oct 21183-day season
- Broomfield CountySpring Apr 20·Fall Oct 21184-day season
- Kiowa CountySpring Apr 19·Fall Oct 21185-day season
- Bent CountySpring Apr 18·Fall Oct 21186-day season
- Logan CountySpring Apr 18·Fall Oct 18183-day season
- Pueblo CountySpring Apr 18·Fall Oct 18183-day season
- Mesa CountySpring Apr 8·Fall Nov 1207-day season
Alphabetical
All Colorado counties — A to Z.
- Adams County
- Alamosa County
- Arapahoe County
- Archuleta County
- Baca County
- Bent County
- Boulder County
- Broomfield County
- Chaffee County
- Cheyenne County
- Clear Creek County
- Conejos County
- Costilla County
- Crowley County
- Custer County
- Delta County
- Denver County
- Dolores County
- Douglas County
- Eagle County
- El Paso County
- Elbert County
- Fremont County
- Garfield County
- Gilpin County
- Grand County
- Gunnison County
- Hinsdale County
- Huerfano County
- Jackson County
- Jefferson County
- Kiowa County
- Kit Carson County
- La Plata County
- Lake County
- Larimer County
- Las Animas County
- Lincoln County
- Logan County
- Mesa County
- Mineral County
- Moffat County
- Montezuma County
- Montrose County
- Morgan County
- Otero County
- Ouray County
- Park County
- Phillips County
- Pitkin County
- Prowers County
- Pueblo County
- Rio Blanco County
- Rio Grande County
- Routt County
- Saguache County
- San Juan County
- San Miguel County
- Sedgwick County
- Summit County
- Teller County
- Washington County
- Weld County
- Yuma County