Frost dates for Downieville, CA
At Downieville, the median last spring frost (32°F) is Apr 28 and the median first fall frost is Oct 25, for a typical growing season of 178 days. For a 90% chance that the last frost has passed, wait until May 22. Nearby ZIP codes are in USDA hardiness zones 8a to 8b.
- Apr 28Last spring frost (median)50% chance of 32°F after this date
- May 22Safer planting date10% chance of 32°F after this date
- Oct 25First fall frost (median)50% chance of 32°F by this date
- 178 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 | May 2 | May 24 | Jun 11 |
| 32°F | Apr 13 | Apr 28 | May 22 |
| 28°F | Mar 10 | Apr 6 | Apr 25 |
| 24°F | Jan 8 | Feb 20 | Mar 30 |
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 | Sep 24 | Oct 8 | Oct 22 |
| 32°F | Oct 9 | Oct 25 | Nov 8 |
| 28°F | Oct 28 | Nov 10 | Dec 1 |
| 24°F | Nov 10 | Dec 1 | Dec 26 |
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 | 110 days | 137 days | 161 days |
| 32°F | 150 days | 178 days | 201 days |
| 28°F | 192 days | 219 days | 254 days |
| 24°F | 244 days | 288 days | 330 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 95944 | 8b | 15 to 20°F | 3 km |
| 95936 | 8a | 10 to 15°F | 5 km |
| 95910 | 8b | 15 to 20°F | 11 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 USC00042500, at 39.5633, -120.8239, elevation 888 m (2,915 ft).
- Data quality: Representative (10+ years), 19 years of freeze data.
- Average days per year at or below 32°F: 112.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Bowman Dam (19 km)
- Strawberry Valley (24 km)
- Lake Spaulding (32 km)
- Blue Canyon Airport (33 km)
- Nevada City (38 km)
- Dobbins 1 S (40 km)
- Portola (40 km)
- Quincy (43 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.