Frost dates for San Jacinto, CA
At San Jacinto, the median last spring frost (32°F) is Jan 31 and the median first fall frost is Dec 10, for a typical growing season of 315 days. For a 90% chance that the last frost has passed, wait until Feb 28. Nearby ZIP codes are in USDA hardiness zone 9b.
- Jan 31Last spring frost (median)50% chance of 32°F after this date
- Feb 28Safer planting date10% chance of 32°F after this date
- Dec 10First fall frost (median)50% chance of 32°F by this date
- 315 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 | Feb 6 | Mar 5 | Apr 8 |
| 32°F | Dec 31 | Jan 31 | Feb 28 |
| 28°F | Dec 11 | Jan 3 | Jan 29 |
| 24°F | Dec 10 | Jan 1 | Jan 14 |
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 5 | Nov 24 | Dec 12 |
| 32°F | Nov 22 | Dec 10 | Jan 6 |
| 28°F | Dec 2 | Dec 21 | Jan 15 |
| 24°F | Dec 9 | Dec 31 | Jan 12 |
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 | 223 days | 260 days | 297 days |
| 32°F | 274 days | 315 days | 348 days |
| 28°F | 330 days | 359 days | 365 days |
| 24°F | 365 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 97% |
| 28°F | 59% |
| 24°F | 11% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 92582 | 9b | 25 to 30°F | 4 km |
| 92583 | 9b | 25 to 30°F | 4 km |
| 92545 | 9b | 25 to 30°F | 9 km |
| 92567 | 9b | 25 to 30°F | 11 km |
| 92548 | 9b | 25 to 30°F | 13 km |
| 92596 | 9b | 25 to 30°F | 16 km |
| 92223 | 9b | 25 to 30°F | 16 km |
| 92220 | 9b | 25 to 30°F | 20 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 USC00047813, at 33.7964, -116.9753, elevation 465 m (1,525 ft).
- Data quality: Representative (10+ years), 26 years of freeze data.
- Average days per year at or below 32°F: 15.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Hemet (10 km)
- Idyllwild Fire Dept (25 km)
- Redlands (34 km)
- Elsinore (36 km)
- Riverside Citrus Exp. (40 km)
- Riverside Fire Station 3 (42 km)
- Palm Springs (43 km)
- Palm Springs Regional Airport (44 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.