Frost dates for Mount Laguna #3, CA
At Mount Laguna #3, the median last spring frost (32°F) is Apr 22 and the median first fall frost is Nov 8, for a typical growing season of 197 days. For a 90% chance that the last frost has passed, wait until May 21. Nearby ZIP codes are in USDA hardiness zones 8a to 8b.
- Apr 22Last spring frost (median)50% chance of 32°F after this date
- May 21Safer planting date10% chance of 32°F after this date
- Nov 8First fall frost (median)50% chance of 32°F by this date
- 197 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 15 | May 10 | Jun 2 |
| 32°F | Mar 25 | Apr 22 | May 21 |
| 28°F | Feb 22 | Apr 2 | May 8 |
| 24°F | Jan 9 | Mar 2 | Apr 21 |
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 1 | Oct 23 | Nov 13 |
| 32°F | Oct 10 | Nov 8 | Dec 4 |
| 28°F | Nov 2 | Dec 1 | Dec 25 |
| 24°F | Nov 18 | Dec 20 | Jan 30 |
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 | 131 days | 164 days | 195 days |
| 32°F | 163 days | 197 days | 232 days |
| 28°F | 195 days | 236 days | 286 days |
| 24°F | 234 days | 288 days | 345 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 97% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 91948 | 8a | 10 to 15°F | 5 km |
| 91962 | 8b | 15 to 20°F | 10 km |
| 91931 | 8b | 15 to 20°F | 15 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 USC00045968, at 32.8672, -116.4194, elevation 1804 m (5,920 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 63.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Cuyamaca (21 km)
- Campo (27 km)
- Campo Asos (27 km)
- Julian Cdf (28 km)
- Alpine (34 km)
- El Capitan Dam (37 km)
- Ocotillo Wells 2w (40 km)
- Borrego Desert Park (43 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.