Frost dates for Cuyamaca, CA
At Cuyamaca, the median last spring frost (32°F) is Apr 19 and the median first fall frost is Oct 27, for a typical growing season of 190 days. For a 90% chance that the last frost has passed, wait until May 14. Nearby ZIP codes are in USDA hardiness zone 9b.
- Apr 19Last spring frost (median)50% chance of 32°F after this date
- May 14Safer planting date10% chance of 32°F after this date
- Oct 27First fall frost (median)50% chance of 32°F by this date
- 190 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 22 | May 13 | Jun 6 |
| 32°F | Mar 24 | Apr 19 | May 14 |
| 28°F | Feb 14 | Mar 14 | Apr 13 |
| 24°F | Jan 10 | Feb 14 | Mar 12 |
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 28 | Oct 12 | Oct 29 |
| 32°F | Oct 9 | Oct 27 | Nov 13 |
| 28°F | Oct 21 | Nov 12 | Dec 4 |
| 24°F | Nov 9 | Dec 4 | Jan 1 |
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 | 123 days | 150 days | 179 days |
| 32°F | 156 days | 190 days | 224 days |
| 28°F | 198 days | 239 days | 278 days |
| 24°F | 253 days | 294 days | 335 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 |
|---|---|---|---|
| 91916 | 9b | 25 to 30°F | 10 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 USC00042239, at 32.9897, -116.5872, elevation 1414 m (4,640 ft).
- Data quality: Representative (10+ years), 25 years of freeze data.
- Average days per year at or below 32°F: 87.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Julian Cdf (10 km)
- Mount Laguna #3 (21 km)
- El Capitan Dam (24 km)
- Alpine (25 km)
- Ramona Fire Dept (30 km)
- Ramona Airport (31 km)
- Henshaw Dam (32 km)
- Borrego Desert Park (34 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.