Frost dates for Vacaville Nut Tree Airport, CA
At Vacaville Nut Tree Airport, the median last spring frost (32°F) is Feb 18 and the median first fall frost is Nov 28, for a typical growing season of 283 days. For a 90% chance that the last frost has passed, wait until Mar 25. Nearby ZIP codes are in USDA hardiness zone 9b.
- Feb 18Last spring frost (median)50% chance of 32°F after this date
- Mar 25Safer planting date10% chance of 32°F after this date
- Nov 28First fall frost (median)50% chance of 32°F by this date
- 283 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 | Feb 26 | Mar 28 | Apr 19 |
| 32°F | Jan 11 | Feb 18 | Mar 25 |
| 28°F | Dec 21 | Jan 15 | Feb 17 |
| 24°F | Dec 11 | Dec 31 | Jan 29 |
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 1 | Nov 13 | Nov 30 |
| 32°F | Nov 12 | Nov 28 | Dec 18 |
| 28°F | Nov 24 | Dec 10 | Jan 11 |
| 24°F | Dec 3 | Dec 21 | Jan 17 |
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 | 201 days | 230 days | 261 days |
| 32°F | 245 days | 283 days | 325 days |
| 28°F | 299 days | 334 days | 365 days |
| 24°F | 338 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 86% |
| 24°F | 43% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 95625 | 9b | 25 to 30°F | 5 km |
| 95687 | 9b | 25 to 30°F | 6 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 USW00093241, at 38.3775, -121.9575, elevation 33 m (109 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 21.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Vacaville (2 km)
- Lake Solano (13 km)
- Fairfield (15 km)
- Winters (17 km)
- Markley Cove (19 km)
- Davis 2 WSW Exp. Farm (24 km)
- Napa State Hospital (29 km)
- Napa Co Airport (34 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.