Frost dates for Ramona Airport, CA
At Ramona Airport, the median last spring frost (32°F) is Mar 19 and the median first fall frost is Nov 23, for a typical growing season of 248 days. For a 90% chance that the last frost has passed, wait until Apr 10. Nearby ZIP codes are in USDA hardiness zones 9b to 10b.
- Mar 19Last spring frost (median)50% chance of 32°F after this date
- Apr 10Safer planting date10% chance of 32°F after this date
- Nov 23First fall frost (median)50% chance of 32°F by this date
- 248 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 28 | Apr 12 | May 1 |
| 32°F | Feb 15 | Mar 19 | Apr 10 |
| 28°F | Dec 30 | Feb 7 | Mar 10 |
| 24°F | Dec 10 | Jan 14 | Feb 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 | Oct 22 | Nov 7 | Nov 23 |
| 32°F | Nov 6 | Nov 23 | Dec 10 |
| 28°F | Nov 21 | Dec 10 | Jan 12 |
| 24°F | Dec 3 | Dec 31 | Feb 3 |
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 | 183 days | 206 days | 231 days |
| 32°F | 221 days | 248 days | 287 days |
| 28°F | 268 days | 309 days | 347 days |
| 24°F | 324 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 96% |
| 24°F | 53% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 92065 | 9b | 25 to 30°F | 8 km |
| 92064 | 10a | 30 to 35°F | 11 km |
| 92025 | 10a | 30 to 35°F | 12 km |
| 92027 | 9b | 25 to 30°F | 12 km |
| 92040 | 10a | 30 to 35°F | 14 km |
| 92128 | 10a | 30 to 35°F | 15 km |
| 92127 | 10a | 30 to 35°F | 20 km |
| 92131 | 10b | 35 to 40°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 USW00053120, at 33.0375, -116.9158, elevation 425 m (1,393 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 40.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Ramona Fire Dept (3 km)
- San Pasqual Animal Pk (10 km)
- Rancho Bernardo (16 km)
- Escondido #2 (19 km)
- El Capitan Dam (19 km)
- Valley Center 1N (23 km)
- Alpine (26 km)
- El Cajon (26 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.