Frost dates for Bowman Dam, CA
At Bowman Dam, the median last spring frost (32°F) is May 12 and the median first fall frost is Oct 29, for a typical growing season of 167 days. For a 90% chance that the last frost has passed, wait until Jun 2. Nearby ZIP codes are in USDA hardiness zone 7a.
- May 12Last spring frost (median)50% chance of 32°F after this date
- Jun 2Safer planting date10% chance of 32°F after this date
- Oct 29First fall frost (median)50% chance of 32°F by this date
- 167 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 9 | May 31 | Jun 17 |
| 32°F | Apr 22 | May 12 | Jun 2 |
| 28°F | Apr 4 | Apr 23 | May 19 |
| 24°F | Mar 14 | Apr 6 | Apr 29 |
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 19 | Oct 11 | Oct 29 |
| 32°F | Oct 10 | Oct 29 | Nov 13 |
| 28°F | Oct 27 | Nov 13 | Nov 30 |
| 24°F | Nov 10 | Nov 28 | Dec 14 |
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 | 108 days | 135 days | 162 days |
| 32°F | 140 days | 167 days | 194 days |
| 28°F | 170 days | 199 days | 227 days |
| 24°F | 205 days | 233 days | 263 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 |
|---|---|---|---|
| 96125 | 7a | 0 to 5°F | 18 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 USC00041018, at 39.4539, -120.6556, elevation 1641 m (5,385 ft).
- Data quality: Representative (10+ years), 16 years of freeze data.
- Average days per year at or below 32°F: 127.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Lake Spaulding (15 km)
- Downieville (19 km)
- Blue Canyon Airport (20 km)
- Sagehen Creek (36 km)
- Nevada City (38 km)
- Donner Mem State Park (39 km)
- Strawberry Valley (41 km)
- Portola (42 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.