San Jose, California: planting zone & frost dates
San Jose is in USDA plant hardiness zone 9b, where the average coldest winter night reaches 25 to 30°F (-3.9 to -1.1°C). The typical last spring frost is around Jan 10 and the first fall frost around Dec 14.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Jan 23 | Dec 4 |
| Typical planning date (30% risk) | Jan 10 | Dec 14 |
| Median (50%) | Jan 2 | Dec 25 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station SAN JOSE, CA (USC00047821), 6.2 mi (9.9 km) from the city center and 95 ft lower than the city center (-29 m). Record used for the 1991–2020 normals: 17 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across San Jose
San Jose spans more than one half-zone. Share of the city's land area by zone (via its 30 ZIP codes): 9b (83%), 10a (17%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
ZIP codes in San Jose and their zones
| ZIP | Zone | Share of city land |
|---|---|---|
| 95037 | 9b | 8.5% |
| 95120 | 9b | 7.6% |
| 95135 | 9b | 6.5% |
| 95134 | 10a | 6.1% |
| 95138 | 9b | 5.9% |
| 95002 | 10a | 5.4% |
| 95123 | 9b | 4.4% |
| 95112 | 9b | 4.1% |
| 95132 | 9b | 4.1% |
| 95125 | 9b | 4.0% |
| 95124 | 9b | 3.4% |
| 95131 | 10a | 3.2% |
| 95111 | 9b | 2.9% |
| 95136 | 9b | 2.9% |
| 95148 | 9b | 2.9% |
| 95122 | 9b | 2.7% |
| 95127 | 9b | 2.7% |
| 95129 | 9b | 2.6% |
| 95110 | 10a | 2.5% |
| 95121 | 9b | 2.5% |
| 95118 | 9b | 2.3% |
| 95116 | 9b | 2.0% |
| 95126 | 9b | 1.9% |
| 95128 | 9b | 1.8% |
| 95133 | 9b | 1.8% |
| 95117 | 9b | 1.3% |
| 95119 | 9b | 1.3% |
| 95130 | 9b | 0.8% |
| 95139 | 9b | 0.6% |
| 95113 | 9b | 0.2% |
Vegetable planting calendar for San Jose
Dates are counted from the 30%-risk frost dates above (last frost Jan 10, first frost Dec 14). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Nov 15 – Nov 29 | Jan 17 – Jan 31 | — | — |
| Pepper | Nov 1 – Nov 15 | Jan 24 – Feb 7 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 29 – Dec 13 | Dec 27 – Jan 17 | Dec 13 – Jan 24 | Oct 5 – Nov 2 |
| Green Beans | — | — | Jan 17 – Feb 21 | Sep 21 – Oct 5 |
| Sweet Corn | — | — | Jan 17 – Feb 14 | — |
| Zucchini & Summer Squash | Dec 13 – Dec 20 | Jan 17 – Jan 31 | Jan 17 – Feb 7 | Sep 21 – Oct 5 |
| Cucumber | Dec 13 – Dec 20 | Jan 24 – Jan 31 | Jan 17 – Feb 7 | Sep 21 – Oct 5 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 20 – Jan 24 | Sep 21 – Oct 5 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Oct 18 – Nov 1 | Dec 13 – Dec 27 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Dec 13 – Jan 3 | — | — |
| Basil | Nov 29 – Dec 13 | Jan 24 – Feb 7 | Jan 24 – Feb 14 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Nov 29 – Dec 27 | Oct 19 – Nov 16 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 15 – Nov 29 | Dec 13 – Jan 3 | Dec 13 – Jan 3 | Oct 5 – Nov 2 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 15 – Nov 29 | Dec 27 – Jan 17 | — | Sep 21 – Oct 5 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Nov 29 – Dec 20 | Oct 5 – Oct 19 |
| Eggplant | Nov 1 – Nov 15 | Jan 24 – Feb 7 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 15 – Nov 29 | Dec 13 – Dec 27 | — | Sep 21 – Oct 5 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 6 – Jan 24 | Nov 2 – Nov 30 |
| Strawberry | — | Dec 13 – Jan 3 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 20 – Jan 31 | Oct 5 – Oct 19 |
Nearby cities in California
- Milpitas — zone 10a, last frost Jan 26, first frost Dec 12
- Santa Clara — zone 9b, last frost Jan 26, first frost Dec 12
- Sunnyvale — zone 9b, last frost Jan 18, first frost Dec 15
- Fremont — zone 9b, last frost Jan 8, first frost Dec 19
- Mountain View — zone 10a, last frost Jan 18, first frost Dec 15
- Livermore — zone 9b, last frost Feb 28, first frost Nov 25
More: all California cities · other zone 9b cities: Houston, TX, Phoenix, AZ, Jacksonville, FL, Fresno, CA, Sacramento, CA, Mesa, AZ, Bakersfield, CA, New Orleans, LA
San Jose gardening questions
When is the last frost in San Jose, CA?
Plan around Jan 10. At NOAA's San Jose, CA station, 6.2 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Jan 2, and after Jan 23 the risk drops to about 1 in 10. The 90% and 10% dates are 40 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in San Jose, CA?
Start seeds indoors Nov 15 – Nov 29 and set transplants outside Jan 17 – Jan 31, once nights stay above 50°F and the soil is near 60°F. With about 338 frost-free days, frost is not the main limit — fruit set drops when nights stay above about 75°F, so early plantings tend to do best. More: tomato planting dates by zone.
How long is the growing season in San Jose?
About 362 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 335 days, and in 1 year in 10 it runs 365 days or more. In fall there is a 10% chance of frost by Dec 4 and a 30% chance by Dec 14. That ranks 27th longest of 84 California cities on this site.
When should I plant a fall garden in San Jose?
Count back from the first fall frost (Dec 14): transplant broccoli Sep 21 – Oct 5; sow kale Oct 5 – Nov 2; sow lettuce Oct 5 – Nov 2; sow radishes Nov 2 – Nov 30. How the math works: succession and fall planting.
Did San Jose's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, San Jose is zone 9b on both the 2012 and the 2023 USDA maps (PRISM/OSU ZIP listings). About 42% of U.S. ZIP codes kept their half-zone in 2023. Why the 2023 map is warmer.
Is all of San Jose in zone 9b?
No. Zone 9b covers about 83% of the city's land; the rest is in 10a (17%), measured across the city's 30 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.