Frost dates for San Luis Dam, CA
At San Luis Dam, the median last spring frost (32°F) is Jan 27 and the median first fall frost is Dec 11, for a typical growing season of 323 days. For a 90% chance that the last frost has passed, wait until Feb 22. Nearby ZIP codes are in USDA hardiness zones 9a to 9b.
- Jan 27Last spring frost (median)50% chance of 32°F after this date
- Feb 22Safer planting date10% chance of 32°F after this date
- Dec 11First fall frost (median)50% chance of 32°F by this date
- 323 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 | Jan 27 | Feb 22 | Mar 20 |
| 32°F | Dec 31 | Jan 27 | Feb 22 |
| 28°F | Dec 17 | Jan 6 | Jan 29 |
| 24°F | Dec 15 | Dec 31 | Jan 19 |
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 13 | Nov 28 | Dec 14 |
| 32°F | Nov 25 | Dec 11 | Jan 6 |
| 28°F | Dec 6 | Dec 24 | Jan 16 |
| 24°F | Dec 10 | Dec 30 | Jan 14 |
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 | 248 days | 281 days | 309 days |
| 32°F | 292 days | 323 days | 352 days |
| 28°F | 334 days | 359 days | 365 days |
| 24°F | 359 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 95% |
| 28°F | 61% |
| 24°F | 18% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 95322 | 9b | 25 to 30°F | 15 km |
| 93635 | 9a | 20 to 25°F | 16 km |
| 95023 | 9b | 25 to 30°F | 28 km |
| 95360 | 9b | 25 to 30°F | 30 km |
| 95075 | 9a | 20 to 25°F | 31 km |
| 95374 | 9a | 20 to 25°F | 34 km |
| 93665 | 9a | 20 to 25°F | 38 km |
| 93620 | 9a | 20 to 25°F | 39 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 USC00047846, at 37.0533, -121.0578, elevation 84 m (277 ft).
- Data quality: Representative (10+ years), 15 years of freeze data.
- Average days per year at or below 32°F: 12.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Los Banos Det Resv (13 km)
- Los Banos (17 km)
- Newman (26 km)
- Merced 23 WSW (26 km)
- Hollister 2 (40 km)
- Gilroy (45 km)
- Paicines 4 W (46 km)
- Turlock #2 (53 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.