Frost dates for Richardson Gr State Park, CA
At Richardson Gr State Park, the median last spring frost (32°F) is Mar 10 and the median first fall frost is Dec 1, for a typical growing season of 271 days. For a 90% chance that the last frost has passed, wait until Apr 13. Nearby ZIP codes are in USDA hardiness zones 9a to 9b.
- Mar 10Last spring frost (median)50% chance of 32°F after this date
- Apr 13Safer planting date10% chance of 32°F after this date
- Dec 1First fall frost (median)50% chance of 32°F by this date
- 271 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 | Mar 16 | Apr 13 | May 7 |
| 32°F | Jan 9 | Mar 10 | Apr 13 |
| 28°F | Dec 10 | Jan 15 | Mar 5 |
| 24°F | Dec 12 | Jan 6 | Jan 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 | Oct 19 | Nov 7 | Dec 2 |
| 32°F | Nov 7 | Dec 1 | Jan 9 |
| 28°F | Nov 25 | Dec 26 | Feb 8 |
| 24°F | Dec 10 | Jan 2 | 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 | 177 days | 209 days | 248 days |
| 32°F | 224 days | 271 days | 331 days |
| 28°F | 293 days | 351 days | 365 days |
| 24°F | 360 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 98% |
| 28°F | 63% |
| 24°F | 13% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 95587 | 9a | 20 to 25°F | 7 km |
| 95542 | 9a | 20 to 25°F | 8 km |
| 95560 | 9b | 25 to 30°F | 14 km |
| 95559 | 9a | 20 to 25°F | 19 km |
| 95585 | 9a | 20 to 25°F | 22 km |
| 95511 | 9a | 20 to 25°F | 24 km |
| 95553 | 9b | 25 to 30°F | 24 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 USC00047404, at 40.0261, -123.7931, elevation 153 m (503 ft).
- Data quality: Representative (10+ years), 15 years of freeze data.
- Average days per year at or below 32°F: 22.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Shelter Cove Aviation (24 km)
- Grizzly Creek State Park (52 km)
- Covelo (52 km)
- Scotia (57 km)
- Fort Bragg 5 N (58 km)
- Willits 1 NE (78 km)
- Eureka WFO Woodley Island (93 km)
- Potter Valley Powerhouse (93 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.