Frost dates for Colfax, CA
At Colfax, the median last spring frost (32°F) is Apr 3 and the median first fall frost is Nov 24, for a typical growing season of 233 days. For a 90% chance that the last frost has passed, wait until Apr 29. Nearby ZIP codes are in USDA hardiness zone 9a.
- Apr 3Last spring frost (median)50% chance of 32°F after this date
- Apr 29Safer planting date10% chance of 32°F after this date
- Nov 24First fall frost (median)50% chance of 32°F by this date
- 233 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Apr 3 | Apr 23 | May 17 |
| 32°F | Feb 28 | Apr 3 | Apr 29 |
| 28°F | Jan 5 | Feb 21 | Apr 6 |
| 24°F | Dec 10 | Jan 9 | Feb 17 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Oct 18 | Nov 7 | Nov 24 |
| 32°F | Nov 2 | Nov 24 | Dec 11 |
| 28°F | Nov 21 | Dec 13 | Jan 14 |
| 24°F | Dec 1 | Jan 1 | Feb 9 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 167 days | 196 days | 223 days |
| 32°F | 198 days | 233 days | 270 days |
| 28°F | 245 days | 294 days | 343 days |
| 24°F | 315 days | 361 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 98% |
| 24°F | 51% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 95713 | 9a | 20 to 25°F | 2 km |
| 95736 | 9a | 20 to 25°F | 6 km |
| 95717 | 9a | 20 to 25°F | 11 km |
| 95722 | 9a | 20 to 25°F | 12 km |
| 95703 | 9a | 20 to 25°F | 12 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00041912, at 39.0911, -120.9481, elevation 725 m (2,380 ft).
- Data quality: Standard (24+ years of data), 24 years of freeze data.
- Average days per year at or below 32°F: 37.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Grass Valley #2 (16 km)
- Nevada City (18 km)
- Georgetown Ranger Station (22 km)
- Auburn (24 km)
- Blue Canyon Airport (29 km)
- Lake Spaulding (37 km)
- Dobbins 1 S (37 km)
- Placerville (45 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.