Frost dates for Merced 23 WSW, CA
At Merced 23 WSW, the median last spring frost (32°F) is Mar 28 and the median first fall frost is Nov 14, for a typical growing season of 233 days. For a 90% chance that the last frost has passed, wait until Apr 27. Nearby ZIP codes are in USDA hardiness zone 9a.
- Mar 28Last spring frost (median)50% chance of 32°F after this date
- Apr 27Safer planting date10% chance of 32°F after this date
- Nov 14First fall frost (median)50% chance of 32°F by this date
- 233 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 6 | Apr 29 | May 25 |
| 32°F | Feb 18 | Mar 28 | Apr 27 |
| 28°F | Jan 4 | Feb 12 | Mar 24 |
| 24°F | Dec 12 | Jan 12 | Feb 13 |
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 9 | Oct 31 | Nov 16 |
| 32°F | Oct 27 | Nov 14 | Dec 1 |
| 28°F | Nov 9 | Nov 29 | Dec 31 |
| 24°F | Nov 22 | Dec 12 | Jan 12 |
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 | 150 days | 183 days | 211 days |
| 32°F | 196 days | 233 days | 274 days |
| 28°F | 253 days | 294 days | 333 days |
| 24°F | 307 days | 340 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 99% |
| 24°F | 79% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 95374 | 9a | 20 to 25°F | 9 km |
| 95334 | 9a | 20 to 25°F | 17 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 USW00093243, at 37.2381, -120.8825, elevation 24 m (78 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 45.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Newman (13 km)
- Los Banos (20 km)
- San Luis Dam (26 km)
- Los Banos Det Resv (28 km)
- Turlock #2 (30 km)
- Merced (33 km)
- Merced Muni Airport (33 km)
- Modesto City Co Airport (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.