Frost dates for New Melones Dam HQ, CA
At New Melones Dam HQ, the median last spring frost (32°F) is Feb 20 and the median first fall frost is Dec 11, for a typical growing season of 290 days. For a 90% chance that the last frost has passed, wait until Apr 7. Nearby ZIP codes are in USDA hardiness zones 9a to 9b.
- Feb 20Last spring frost (median)50% chance of 32°F after this date
- Apr 7Safer planting date10% chance of 32°F after this date
- Dec 11First fall frost (median)50% chance of 32°F by this date
- 290 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 1 | Apr 7 | May 5 |
| 32°F | Jan 10 | Feb 20 | Apr 7 |
| 28°F | Dec 16 | Jan 6 | Feb 15 |
| 24°F | Dec 12 | Dec 25 | Jan 15 |
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 3 | Nov 24 | Dec 12 |
| 32°F | Nov 24 | Dec 11 | Jan 8 |
| 28°F | Dec 5 | Dec 24 | Feb 1 |
| 24°F | Dec 10 | Dec 25 | Jan 5 |
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 | 194 days | 229 days | 270 days |
| 32°F | 238 days | 290 days | 335 days |
| 28°F | 320 days | 358 days | 365 days |
| 24°F | 364 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 99% |
| 28°F | 60% |
| 24°F | 12% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 95251 | 9a | 20 to 25°F | 9 km |
| 95221 | 9a | 20 to 25°F | 9 km |
| 95222 | 9a | 20 to 25°F | 10 km |
| 95310 | 9a | 20 to 25°F | 13 km |
| 95247 | 9a | 20 to 25°F | 15 km |
| 95228 | 9b | 25 to 30°F | 21 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 USC00046174, at 38.0047, -120.4864, elevation 293 m (960 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 13.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Sonora (10 km)
- Groveland 2 (29 km)
- Calaveras Big Trees (34 km)
- Camp Pardee (41 km)
- Sutter Hill Cdf (50 km)
- Cherry Valley Dam (50 km)
- Modesto City Co Airport (59 km)
- Hetch Hetchy (62 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.