Frost dates for Oroville, CA
At Oroville, the median last spring frost (32°F) is Jan 30 and the median first fall frost is Dec 13, for a typical growing season of 321 days. For a 90% chance that the last frost has passed, wait until Mar 3. Nearby ZIP codes are in USDA hardiness zone 9b.
- Jan 30Last spring frost (median)50% chance of 32°F after this date
- Mar 3Safer planting date10% chance of 32°F after this date
- Dec 13First fall frost (median)50% chance of 32°F by this date
- 321 daysGrowing season (median)between 32°F freezes
USDA hardiness zone 9b (25 to 30°F) · see all zone 9b frost dates
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 | Feb 3 | Mar 8 | Apr 17 |
| 32°F | Dec 26 | Jan 30 | Mar 3 |
| 28°F | Dec 14 | Jan 5 | Feb 4 |
| 24°F | Dec 11 | Dec 30 | Jan 26 |
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 | Nov 8 | Nov 27 | Dec 18 |
| 32°F | Nov 21 | Dec 13 | Jan 11 |
| 28°F | Dec 5 | Dec 25 | Jan 25 |
| 24°F | Dec 10 | Dec 27 | Jan 24 |
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 | 219 days | 263 days | 305 days |
| 32°F | 276 days | 321 days | 357 days |
| 28°F | 331 days | 361 days | 365 days |
| 24°F | 357 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 94% |
| 28°F | 55% |
| 24°F | 18% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 95965 | 9b | 25 to 30°F | 9 km |
| 95966 | 9b | 25 to 30°F | 13 km |
| 95916 | 9b | 25 to 30°F | 21 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 USC00046521, at 39.5178, -121.5531, elevation 52 m (171 ft).
- Data quality: Representative (10+ years), 19 years of freeze data.
- Average days per year at or below 32°F: 16.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Oroville Muni Airport (6 km)
- Paradise (27 km)
- Chico Univ Farm (30 km)
- Dobbins 1 S (35 km)
- Strawberry Valley (39 km)
- De Sabla (40 km)
- Marysville (41 km)
- Marysville Yuba Co Airport (46 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.