Chino Hills, California: planting zone & frost dates
Chino Hills is in USDA plant hardiness zone 10a, where the average coldest winter night reaches 30 to 35°F (-1.1 to 1.7°C). The typical last spring frost is around Feb 3 and the first fall frost around Dec 10.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Feb 22 | Nov 27 |
| Typical planning date (30% risk) | Feb 3 | Dec 10 |
| Median (50%) | Jan 17 | Dec 19 |
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 CHINO AP, CA (USW00003179), 5.6 mi (9.0 km) from the city center and 443 ft lower than the city center (-135 m). Record used for the 1991–2020 normals: 18 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Chino Hills
All 1 ZIP code covering Chino Hills is in zone 10a.
ZIP codes in Chino Hills and their zones
| ZIP | Zone | Share of city land |
|---|---|---|
| 91709 | 10a | 100.0% |
Vegetable planting calendar for Chino Hills
Dates are counted from the 30%-risk frost dates above (last frost Feb 3, first frost Dec 10). 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 9 – Dec 23 | Feb 10 – Feb 24 | — | — |
| Pepper | Nov 25 – Dec 9 | Feb 17 – Mar 3 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 23 – Jan 6 | Jan 20 – Feb 10 | Jan 6 – Feb 17 | Oct 1 – Oct 29 |
| Green Beans | — | — | Feb 10 – Mar 17 | Sep 17 – Oct 1 |
| Sweet Corn | — | — | Feb 10 – Mar 10 | — |
| Zucchini & Summer Squash | Jan 6 – Jan 13 | Feb 10 – Feb 24 | Feb 10 – Mar 3 | Sep 17 – Oct 1 |
| Cucumber | Jan 6 – Jan 13 | Feb 17 – Feb 24 | Feb 10 – Mar 3 | Sep 17 – Oct 1 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 13 – Feb 17 | Sep 17 – Oct 1 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 11 – Nov 25 | Jan 6 – Jan 20 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Jan 6 – Jan 27 | — | — |
| Basil | Dec 23 – Jan 6 | Feb 17 – Mar 3 | Feb 17 – Mar 10 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 23 – Jan 20 | Oct 15 – Nov 12 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 9 – Dec 23 | Jan 6 – Jan 27 | Jan 6 – Jan 27 | Oct 1 – Oct 29 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 9 – Dec 23 | Jan 20 – Feb 10 | — | Sep 17 – Oct 1 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 23 – Jan 13 | Oct 1 – Oct 15 |
| Eggplant | Nov 25 – Dec 9 | Feb 17 – Mar 3 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 9 – Dec 23 | Jan 6 – Jan 20 | — | Sep 17 – Oct 1 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 30 – Feb 17 | Oct 29 – Nov 26 |
| Strawberry | — | Jan 6 – Jan 27 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 13 – Feb 24 | Oct 1 – Oct 15 |
Nearby cities in California
- Chino — zone 10a, last frost Feb 3, first frost Dec 10
- Anaheim — zone 10b, frost rare
- Pomona — zone 10a, last frost Jan 26, first frost Dec 19
- Ontario — zone 10a, last frost Jan 13, first frost Dec 22
- Corona — zone 10a, last frost Jan 29, first frost Dec 19
- Upland — zone 10a, last frost Jan 26, first frost Dec 19
More: all California cities · other zone 10a cities: Los Angeles, CA, Oakland, CA, Tampa, FL, Orlando, FL, Riverside, CA, Corpus Christi, TX, Port St. Lucie, FL, Scottsdale, AZ
Chino Hills gardening questions
When is the last frost in Chino Hills, CA?
Plan around Feb 3. At NOAA's Chino Airport, CA station, 5.6 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 17, and after Feb 22 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Jan 3. Springs here are erratic: 66 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 Chino Hills, CA?
Start seeds indoors Dec 9 – Dec 23 and set transplants outside Feb 10 – Feb 24, once nights stay above 50°F and the soil is near 60°F. With about 310 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 Chino Hills?
About 335 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 293 days, and in 1 year in 10 it runs 365 days or more. In fall there is a 10% chance of frost by Nov 27 and a 30% chance by Dec 10. That ranks 51st longest of 84 California cities on this site.
When should I plant a fall garden in Chino Hills?
Count back from the first fall frost (Dec 10): transplant broccoli Sep 17 – Oct 1; sow kale Oct 1 – Oct 29; sow lettuce Oct 1 – Oct 29; sow radishes Oct 29 – Nov 26. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Dec 30. How the math works: succession and fall planting.
Did Chino Hills's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Chino Hills is zone 10a 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 Chino Hills compare with Anaheim, CA?
Chino Hills is zone 10a and Anaheim is zone 10b. Frost is rare in Anaheim, but Chino Hills (6 miles away) has a typical last frost around Feb 3 — see Anaheim, CA.