Frost dates in California
Across California, the typical last spring frost is around Feb 9 and the first fall frost around Dec 1. Your own dates depend on where you are in the state; find your county below.
Most of the state's last spring frosts fall between Jan 6 and May 16, and its first fall frosts between Jan 14 and Dec 25. In about 17% of the state's ZIP codes, frost is rare.
These are the dates with a 50% chance of a 32°F frost on or after (spring) or on or before (fall), so plan tender crops a week or two after the spring date and keep row cover handy. For dates at your exact ZIP code, use the zone and frost date lookup; for what to plant when, see the planting guide by frost date.
Hardiness zones in California: zone 5b, zone 6a, zone 6b, zone 7a, zone 7b, zone 8a, zone 8b, zone 9a, zone 9b, zone 10a, zone 10b, zone 11a
Frost dates by county in California
| County | Last spring frost | First fall frost | Growing season |
|---|---|---|---|
| Alameda | Jan 3 | Dec 22 | About 353 days |
| Alpine | May 30 | Sep 28 | About 121 days |
| Amador | Mar 4 | Dec 11 | About 282 days |
| Butte | Mar 4 | Nov 17 | About 258 days |
| Calaveras | Feb 20 | Dec 11 | About 294 days |
| Colusa | Feb 14 | Dec 1 | About 290 days |
| Contra Costa | Jan 12 | Dec 19 | About 341 days |
| Del Norte | Mar 11 | Nov 23 | About 257 days |
| El Dorado | Apr 12 | Nov 21 | About 223 days |
| Fresno | Jan 30 | Dec 11 | About 315 days |
| Glenn | Feb 25 | Dec 2 | About 280 days |
| Humboldt | Mar 4 | Dec 1 | About 272 days |
| Imperial | Jan 6 | Dec 21 | About 349 days |
| Inyo | Mar 31 | Nov 3 | About 217 days |
| Kern | Feb 20 | Nov 26 | About 279 days |
| Kings | Feb 19 | Nov 29 | About 283 days |
| Lake | Apr 10 | Nov 6 | About 210 days |
| Lassen | May 28 | Oct 1 | About 126 days |
| Los Angeles | Jan 8 | Nov 15 | About 311 days |
| Madera | Mar 25 | Nov 27 | About 247 days |
| Marin | Jan 11 | Dec 21 | About 344 days |
| Mariposa | May 12 | Nov 1 | About 173 days |
| Mendocino | Mar 10 | Nov 21 | About 256 days |
| Merced | Feb 26 | Nov 25 | About 272 days |
| Modoc | May 28 | Sep 29 | About 124 days |
| Mono | May 23 | Oct 9 | About 139 days |
| Monterey | Feb 4 | Dec 8 | About 307 days |
| Napa | Mar 6 | Dec 4 | About 273 days |
| Nevada | May 4 | Nov 13 | About 193 days |
| Orange | Jan 6 | Jan 2 | About -4 days |
| Placer | Apr 3 | Nov 24 | About 235 days |
| Plumas | May 22 | Sep 25 | About 126 days |
| Riverside | Jan 27 | Dec 18 | About 325 days |
| Sacramento | Jan 12 | Dec 16 | About 338 days |
| San Benito | Apr 14 | Dec 1 | About 231 days |
| San Bernardino | Feb 19 | Nov 28 | About 282 days |
| San Diego | Jan 30 | Dec 4 | About 308 days |
| San Francisco | Dec 30 | Dec 25 | About -5 days |
| San Joaquin | Feb 6 | Dec 5 | About 302 days |
| San Luis Obispo | Feb 1 | Nov 10 | About 282 days |
| San Mateo | Feb 25 | Dec 12 | About 290 days |
| Santa Barbara | Jan 20 | Dec 4 | About 318 days |
| Santa Clara | Jan 12 | Dec 22 | About 344 days |
| Santa Cruz | Jan 31 | Dec 9 | About 312 days |
| Shasta | Mar 19 | Nov 21 | About 247 days |
| Sierra | May 9 | Oct 25 | About 169 days |
| Siskiyou | May 6 | Oct 12 | About 159 days |
| Solano | Jan 17 | Dec 14 | About 331 days |
| Sonoma | Feb 26 | Dec 2 | About 279 days |
| Stanislaus | Jan 31 | Dec 5 | About 308 days |
| Sutter | Feb 11 | Nov 30 | About 292 days |
| Tehama | Feb 25 | Nov 29 | About 277 days |
| Trinity | Apr 23 | Oct 22 | About 182 days |
| Tulare | Feb 5 | Dec 8 | About 306 days |
| Tuolumne | Apr 16 | Nov 9 | About 207 days |
| Ventura | Mar 21 | Dec 15 | About 269 days |
| Yolo | Feb 7 | Dec 5 | About 301 days |
| Yuba | Apr 1 | Nov 17 | About 230 days |
Source: NOAA NCEI U.S. Climate Normals 1991–2020, 50% probability of 32°F, from the weather station nearest each ZIP code; each county shows the middle value across its ZIP codes. Hills, valleys and cities can run a week or more earlier or later.