When Is the Last Frost in California?
The average last spring frost in California falls between January 5 and May 16 for most ZIP codes, with a statewide median of February 6. At the average date a later frost is still a coin flip, so tender plants wait for the safer 90% date.
| City | Last frost | 90% safe after | First frost | Growing season |
|---|---|---|---|---|
| Los Angeles | Frost-free | Frost-free | Frost-free | 365 days |
| San Diego | Frost-free | Frost-free | Frost-free | 365 days |
| San Jose | Jan 2 | Jan 23 | Dec 25 | 362 days |
| San Francisco | Jan 16 | Feb 25 | Dec 18 | 334 days |
| Fresno | Jan 14 | Feb 11 | Dec 14 | 337 days |
| Sacramento | Jan 12 | Feb 8 | Dec 16 | 341 days |
| Long Beachfrost in <50% of winters | Jan 9 | Feb 24 | Jan 5 | 365 days |
| Oakland | Jan 7 | Feb 8 | Dec 23 | 356 days |
| Bakersfield | Jan 31 | Feb 27 | Dec 8 | 312 days |
| Anaheim | Jan 17 | Feb 22 | Dec 19 | 335 days |
| Stockton | Feb 5 | Mar 11 | Dec 8 | 305 days |
| Riverside | Jan 9 | Feb 25 | Dec 25 | 353 days |
| Santa Claritafrost in <50% of winters | Jan 8 | Mar 10 | Jan 1 | 365 days |
| Modesto | Jan 31 | Feb 25 | Dec 5 | 312 days |
| Oxnardfrost in <50% of winters | Dec 29 | Jan 15 | Dec 24 | 365 days |
| Santa Rosa | Feb 25 | Mar 29 | Dec 1 | 279 days |
| Rancho Cucamongafrost in <50% of winters | Jan 4 | Feb 7 | Dec 30 | 365 days |
| Oceanside | Jan 23 | Feb 22 | Dec 11 | 325 days |
| Palmdale | Mar 10 | Apr 11 | Nov 19 | 248 days |
Last and first frost: 50% (median) dates of the last spring and first fall 32 °F night. 90% safe after: only a 10% chance of a later spring frost. First frost dates in January fall in the following winter. Each city uses the NOAA station nearest the ZIP code closest to its center.
Across all 332 California weather stations with frost records, median last frost dates run from January 1 at Death Valley Np, CA to December 31 at Indio Fire Stn, CA. Elevation, valleys that collect cold air and distance from large water bodies explain most of the spread, so a garden a few miles from a listed city can differ by a week or more. The ZIP code lookup above uses the same NOAA data as the frost date calculator for every US ZIP code.
When Is the First Frost in California?
The average first fall frost in California arrives between October 26 and January 2 for most ZIP codes, with a median of December 10. Tomatoes, peppers, basil and squash are damaged at 32 °F, so harvest or cover them before then.
Fall frost can come early: San Jose has a 10% chance of frost before December 4, San Francisco has a 10% chance of frost before November 30 and Fresno has a 10% chance of frost before November 29. Hardy crops such as kale, spinach and cabbage tolerate light frosts and keep producing after the first frost date.
When to Plant Tomatoes in California?
Transplant tomatoes in California 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: Jan 9 – Jan 16 in San Jose, Jan 23 – Jan 30 in San Francisco and Jan 21 – Jan 28 in Fresno. Start seeds indoors 6 to 8 weeks before the last frost.
| City | Start seeds indoors | Transplant outdoors | Lowest-risk transplant |
|---|---|---|---|
| Los Angeles | — | No frost date; plant by season | — |
| San Diego | — | No frost date; plant by season | — |
| San Jose | Nov 7 – Nov 21 | Jan 9 – Jan 16 | after Jan 23 |
| San Francisco | Nov 21 – Dec 5 | Jan 23 – Jan 30 | after Feb 25 |
| Fresno | Nov 19 – Dec 3 | Jan 21 – Jan 28 | after Feb 11 |
| Sacramento | Nov 17 – Dec 1 | Jan 19 – Jan 26 | after Feb 8 |
| Long Beach | Nov 14 – Nov 28 | Jan 16 – Jan 23 | after Feb 24 |
| Oakland | Nov 12 – Nov 26 | Jan 14 – Jan 21 | after Feb 8 |
| Bakersfield | Dec 6 – Dec 20 | Feb 7 – Feb 14 | after Feb 27 |
| Anaheim | Nov 22 – Dec 6 | Jan 24 – Jan 31 | after Feb 22 |
| Stockton | Dec 11 – Dec 25 | Feb 12 – Feb 19 | after Mar 11 |
| Riverside | Nov 14 – Nov 28 | Jan 16 – Jan 23 | after Feb 25 |
| Santa Clarita | Nov 13 – Nov 27 | Jan 15 – Jan 22 | after Mar 10 |
| Modesto | Dec 6 – Dec 20 | Feb 7 – Feb 14 | after Feb 25 |
| Oxnard | Nov 3 – Nov 17 | Jan 5 – Jan 12 | after Jan 15 |
| Santa Rosa | Dec 31 – Jan 14 | Mar 4 – Mar 11 | after Mar 29 |
| Rancho Cucamonga | Nov 9 – Nov 23 | Jan 11 – Jan 18 | after Feb 7 |
| Oceanside | Nov 28 – Dec 12 | Jan 30 – Feb 6 | after Feb 22 |
| Palmdale | Jan 13 – Jan 27 | Mar 17 – Mar 24 | after Apr 11 |
Indoors: 6–8 weeks before the average last frost. Outdoors: 1–2 weeks after it. Lowest-risk: after the date with only a 10% chance of a later frost. Rules of thumb; check the 10-day forecast and wait for soil near 60 °F.
Tomatoes stall below about 50 °F at night and are killed by frost, so a week or two of waiting after the average date costs little. The tomato plant care guide covers light, watering and feeding once plants are in the ground. In frost-free or rare-frost areas such as Los Angeles, San Diego and Long Beach, summer heat limits tomatoes more than frost: flowers often drop without setting fruit when nights stay above about 75 °F, so gardeners there typically plant in late winter and again for a fall crop.
What Can You Plant in San Jose and When?
San Jose's average last frost of January 2 anchors its spring planting calendar: peas and spinach go in from November 21, broccoli and lettuce transplants from December 5, and tomatoes, peppers and squash after January 9.
| Crop | Start seeds indoors | Plant outdoors | Frost tolerance |
|---|---|---|---|
| Peas | — | Nov 21 – Dec 5direct sow, 4–6 weeks before last frost | hardy |
| Spinach | — | Nov 21 – Dec 12direct sow, 3–6 weeks before last frost | hardy |
| Radishes | — | Nov 28 – Dec 12direct sow, 3–5 weeks before last frost | hardy |
| Onions (sets) | — | Dec 5 – Dec 19plant, 2–4 weeks before last frost | hardy |
| Potatoes | — | Dec 5 – Dec 19plant, 2–4 weeks before last frost | half-hardy |
| Broccoli & cabbage | Nov 7 – Nov 21 | Dec 5 – Dec 19transplant, 2–4 weeks before last frost | hardy |
| Lettuce | Nov 21 – Dec 5 | Dec 5 – Dec 19transplant, 2–4 weeks before last frost | hardy |
| Beets | — | Dec 5 – Dec 19direct sow, 2–4 weeks before last frost | half-hardy |
| Carrots | — | Dec 12 – Dec 19direct sow, 2–3 weeks before last frost | half-hardy |
| Tomatoes | Nov 7 – Nov 21 | Jan 9 – Jan 16transplant, 1–2 weeks after last frost | tender |
| Basil | Nov 7 – Nov 21 | Jan 9 – Jan 23transplant, 1–3 weeks after last frost | tender |
| Peppers | Oct 24 – Nov 7 | Jan 16 – Jan 23transplant, 2–3 weeks after last frost | tender |
| Eggplant | Oct 24 – Nov 7 | Jan 16 – Jan 23transplant, 2–3 weeks after last frost | tender |
| Green beans | — | Jan 9 – Jan 23direct sow, 1–3 weeks after last frost | tender |
| Sweet corn | — | Jan 9 – Jan 23direct sow, 1–3 weeks after last frost | tender |
| Cucumbers | Dec 5 – Dec 12 | Jan 9 – Jan 23transplant, 1–3 weeks after last frost | tender |
| Squash & zucchini | Dec 5 – Dec 12 | Jan 9 – Jan 23transplant, 1–3 weeks after last frost | tender |
| Watermelon | Dec 5 – Dec 12 | Jan 16 – Jan 23transplant, 2–3 weeks after last frost | tender |
Dates for San Jose (last frost Jan 2, NOAA station San Jose, CA, 6 miles from ZIP 95121). General rules of thumb; wait for soil near 50 °F for most seeds and 60 °F for beans, corn and squash.
How Long Is the Growing Season in California?
The frost-free growing season in California lasts about 174 to 365 days for most ZIP codes, with a median of 312 days. Among the listed cities, Palmdale has the shortest season at 248 days and Rancho Cucamonga the longest at 365.
Season length decides which varieties ripen: compare it with the “days to maturity” on seed packets, counted from transplanting for tomatoes and peppers. NOAA stations in California range from 91 days at Portola, CA to 365 days at Berkeley, CA. Planning beds before the season starts helps in short seasons — a plant spacing calculator for vegetable beds shows how many transplants fit.
What Hardiness Zones Are in California?
California spans USDA hardiness zones 5b to 11a, with zone 9b the most common. Zones describe winter cold and decide which perennials survive, while frost dates set when to plant annual vegetables and flowers.
The California planting zone map with the zone of each city shows how the zones are spread across the state and which plants are hardy in all of them.
Frequently Asked Questions
- When is the last frost in California?
- The average last spring frost in California falls between January 5 and May 16 for most ZIP codes, with a statewide median of February 6. Among major cities it ranges from January 2 in San Jose to December 29 in Oxnard.
- When is the last frost in San Jose, California?
- San Jose's average last spring frost is January 2, and by January 23 the chance of a later frost drops to 10%. Its first fall frost averages December 25, giving a 362-day growing season (NOAA station San Jose, CA).
- When should you plant tomatoes in California?
- Transplant tomatoes in California 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: Jan 9 – Jan 16 in San Jose, Jan 23 – Jan 30 in San Francisco and Jan 21 – Jan 28 in Fresno. Start seeds indoors 6 to 8 weeks before the last frost.
- When is the first frost in California?
- The average first fall frost in California arrives between October 26 and January 2 for most ZIP codes, with a median of December 10. Harvest tender crops such as tomatoes, peppers and basil before then or cover them on cold nights.
- How long is the growing season in California?
- The frost-free growing season in California lasts about 174 to 365 days for most ZIP codes, with a median of 312 days, from 248 days in Palmdale to 365 days in Rancho Cucamonga.
Frost data: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals (32 °F freeze dates by probability). ZIP code and city locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. Planting windows are general rules of thumb. PlantoScan is not affiliated with or endorsed by these agencies.