Manteca, California: planting zone & frost dates
Manteca 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 17 and the first fall frost around Nov 24.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Feb 28 | Nov 15 |
| Typical planning date (30% risk) | Feb 17 | Nov 24 |
| Median (50%) | Feb 6 | Dec 1 |
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 METRO AP, CA (USW00023237), 6.8 mi (11.0 km) from the city center and 7 ft lower than the city center (-2 m). Record used for the 1991–2020 normals: 29 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Manteca
All 4 ZIP codes covering Manteca are in zone 9b.
Vegetable planting calendar for Manteca
Dates are counted from the 30%-risk frost dates above (last frost Feb 17, first frost Nov 24). 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 23 – Jan 6 | Feb 24 – Mar 10 | — | — |
| Pepper | Dec 9 – Dec 23 | Mar 3 – Mar 17 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Jan 6 – Jan 20 | Feb 3 – Feb 24 | Jan 20 – Mar 3 | Sep 15 – Oct 13 |
| Green Beans | — | — | Feb 24 – Mar 31 | Sep 1 – Sep 15 |
| Sweet Corn | — | — | Feb 24 – Mar 24 | — |
| Zucchini & Summer Squash | Jan 20 – Jan 27 | Feb 24 – Mar 10 | Feb 24 – Mar 17 | Sep 1 – Sep 15 |
| Cucumber | Jan 20 – Jan 27 | Mar 3 – Mar 10 | Feb 24 – Mar 17 | Sep 1 – Sep 15 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 27 – Mar 3 | Sep 1 – Sep 15 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 25 – Dec 9 | Jan 20 – Feb 3 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Jan 20 – Feb 10 | — | — |
| Basil | Jan 6 – Jan 20 | Mar 3 – Mar 17 | Mar 3 – Mar 24 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 6 – Feb 3 | Sep 29 – Oct 27 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 23 – Jan 6 | Jan 20 – Feb 10 | Jan 20 – Feb 10 | Sep 15 – Oct 13 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 23 – Jan 6 | Feb 3 – Feb 24 | — | Sep 1 – Sep 15 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 6 – Jan 27 | Sep 15 – Sep 29 |
| Eggplant | Dec 9 – Dec 23 | Mar 3 – Mar 17 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 23 – Jan 6 | Jan 20 – Feb 3 | — | Sep 1 – Sep 15 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 13 – Mar 3 | Oct 13 – Nov 10 |
| Strawberry | — | Jan 20 – Feb 10 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 27 – Mar 10 | Sep 15 – Sep 29 |
Nearby cities in California
- Stockton — zone 9b, last frost Feb 19, first frost Nov 28
- Tracy — zone 9b, last frost Mar 9, first frost Nov 20
- Modesto — zone 9b, last frost Feb 10, first frost Nov 29
- Livermore — zone 9b, last frost Feb 28, first frost Nov 25
- Antioch — zone 9b, last frost Jan 22, first frost Dec 10
- Elk Grove — zone 9b, last frost Feb 17, first frost Nov 26
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
Manteca gardening questions
When is the last frost in Manteca, CA?
Plan around Feb 17. At NOAA's Stockton Metro Airport, CA station, 6.8 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 6, and after Feb 28 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Jan 10. Springs here are erratic: 59 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 Manteca, CA?
Start seeds indoors Dec 23 – Jan 6 and set transplants outside Feb 24 – Mar 10, once nights stay above 50°F and the soil is near 60°F. With about 280 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 Manteca?
About 304 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 271 days, and in 1 year in 10 it runs 339 days or more. In fall there is a 10% chance of frost by Nov 15 and a 30% chance by Nov 24. That ranks 68th longest of 84 California cities on this site.
When should I plant a fall garden in Manteca?
Count back from the first fall frost (Nov 24): transplant broccoli Sep 1 – Sep 15; sow kale Sep 15 – Oct 13; sow lettuce Sep 15 – Oct 13; sow radishes Oct 13 – Nov 10. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Dec 16. How the math works: succession and fall planting.
Did Manteca's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Manteca 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.
How does Manteca compare with Tracy, CA?
Both are in zone 9b. The typical last spring frost in Manteca (Feb 17) comes about 20 days earlier than in Tracy, CA (Mar 9), 13 miles away, and the first fall frost is Nov 24 versus Nov 20. The two cities use different NOAA stations.