Stockton, California: planting zone & frost dates
Stockton 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 Feb 19 and the first fall frost around Nov 28.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Mar 11 | Nov 17 |
| Typical planning date (30% risk) | Feb 19 | Nov 28 |
| Median (50%) | Feb 5 | Dec 8 |
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 STOCKTON FIRE STN 4, CA (USC00048560), 1.7 mi (2.7 km) from the city center and about the same elevation as the city center (+0 m). Record used for the 1991–2020 normals: 15 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Stockton
All 11 ZIP codes covering Stockton are in zone 9b.
Vegetable planting calendar for Stockton
Dates are counted from the 30%-risk frost dates above (last frost Feb 19, first frost Nov 28). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Dec 25 – Jan 8 | Feb 26 – Mar 12 | — | — |
| Pepper | Dec 11 – Dec 25 | Mar 5 – Mar 19 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Jan 8 – Jan 22 | Feb 5 – Feb 26 | Jan 22 – Mar 5 | Sep 19 – Oct 17 |
| Green Beans | — | — | Feb 26 – Apr 2 | Sep 5 – Sep 19 |
| Sweet Corn | — | — | Feb 26 – Mar 26 | — |
| Zucchini & Summer Squash | Jan 22 – Jan 29 | Feb 26 – Mar 12 | Feb 26 – Mar 19 | Sep 5 – Sep 19 |
| Cucumber | Jan 22 – Jan 29 | Mar 5 – Mar 12 | Feb 26 – Mar 19 | Sep 5 – Sep 19 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 29 – Mar 5 | Sep 5 – Sep 19 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 27 – Dec 11 | Jan 22 – Feb 5 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Jan 22 – Feb 12 | — | — |
| Basil | Jan 8 – Jan 22 | Mar 5 – Mar 19 | Mar 5 – Mar 26 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 8 – Feb 5 | Oct 3 – Oct 31 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 25 – Jan 8 | Jan 22 – Feb 12 | Jan 22 – Feb 12 | Sep 19 – Oct 17 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 25 – Jan 8 | Feb 5 – Feb 26 | — | Sep 5 – Sep 19 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 8 – Jan 29 | Sep 19 – Oct 3 |
| Eggplant | Dec 11 – Dec 25 | Mar 5 – Mar 19 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 25 – Jan 8 | Jan 22 – Feb 5 | — | Sep 5 – Sep 19 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 15 – Mar 5 | Oct 17 – Nov 14 |
| Strawberry | — | Jan 22 – Feb 12 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 29 – Mar 12 | Sep 19 – Oct 3 |
Nearby cities in California
- Manteca — zone 9b, last frost Feb 17, first frost Nov 24
- Tracy — zone 9b, last frost Mar 9, first frost Nov 20
- Elk Grove — zone 9b, last frost Feb 17, first frost Nov 26
- Modesto — zone 9b, last frost Feb 10, first frost Nov 29
- Antioch — zone 9b, last frost Jan 22, first frost Dec 10
- 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, San Jose, CA, Fresno, CA, Sacramento, CA, Mesa, AZ, Bakersfield, CA
Stockton gardening questions
When is the last frost in Stockton, CA?
Plan around Feb 19. At NOAA's Stockton Fire Stn 4, CA station, 1.7 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 Feb 5, and after Mar 11 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Jan 11. Springs here are erratic: 74 days separate the 90% and 10% dates, versus a median of 36 days for cities on this site, so watch the forecast rather than the calendar.
When should I plant tomatoes in Stockton, CA?
Start seeds indoors Dec 25 – Jan 8 and set transplants outside Feb 26 – Mar 12, once nights stay above 50°F and the soil is near 60°F. With about 282 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 Stockton?
About 305 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 262 days, and in 1 year in 10 it runs 344 days or more. In fall there is a 10% chance of frost by Nov 17 and a 30% chance by Nov 28. That ranks 67th longest of 84 California cities on this site.
When should I plant a fall garden in Stockton?
Count back from the first fall frost (Nov 28): transplant broccoli Sep 5 – Sep 19; sow kale Sep 19 – Oct 17; sow lettuce Sep 19 – Oct 17; sow radishes Oct 17 – Nov 14. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Dec 23. How the math works: succession and fall planting.
Did Stockton's hardiness zone change on the 2023 map?
Yes. Most of Stockton was zone 9a on the 2012 map and is zone 9b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
How does Stockton compare with Manteca, CA?
Both are in zone 9b. The typical last spring frost in Stockton (Feb 19) comes about the same time as in Manteca, CA (Feb 17), 14 miles away, and the first fall frost is Nov 28 versus Nov 24. The two cities use different NOAA stations.