Frost dates for East Park Rsvr, CA
At East Park Rsvr, the median last spring frost (32°F) is Apr 6 and the median first fall frost is Nov 10, for a typical growing season of 219 days. For a 90% chance that the last frost has passed, wait until Apr 25. Nearby ZIP codes are in USDA hardiness zone 9a.
- Apr 6Last spring frost (median)50% chance of 32°F after this date
- Apr 25Safer planting date10% chance of 32°F after this date
- Nov 10First fall frost (median)50% chance of 32°F by this date
- 219 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 11 | Apr 25 | May 14 |
| 32°F | Mar 6 | Apr 6 | Apr 25 |
| 28°F | Feb 5 | Mar 2 | Apr 11 |
| 24°F | Dec 28 | Jan 30 | Feb 28 |
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 13 | Nov 1 | Nov 12 |
| 32°F | Oct 27 | Nov 10 | Nov 23 |
| 28°F | Nov 8 | Nov 24 | Dec 12 |
| 24°F | Nov 21 | Dec 8 | Jan 11 |
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 | 163 days | 188 days | 211 days |
| 32°F | 194 days | 219 days | 250 days |
| 28°F | 227 days | 267 days | 300 days |
| 24°F | 283 days | 319 days | 351 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 94% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 95979 | 9a | 20 to 25°F | 8 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 USC00042640, at 39.3592, -122.5178, elevation 367 m (1,205 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 60.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Stony Gorge Rsvr (25 km)
- Willows 6 W (26 km)
- Colusa 2 SSW (46 km)
- Clearlake 4 SE (49 km)
- Orland (51 km)
- Potter Valley Powerhouse (53 km)
- Ukiah (64 km)
- Ukiah Muni Airport (64 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.