San Jacinto, CA planting zone & frost dates
San Jacinto is in USDA hardiness zone 9b. The last spring frost usually comes around January 31 and the first fall frost around December 10, for a growing season of about 315 days.
Planting calendar for San Jacinto
Dates are counted from the average last spring frost (January 31) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Dec 6 – Dec 20 Transplant outdoors: Feb 7 – Feb 14 |
| Peppers | Start seeds indoors: Nov 22 – Dec 6 Transplant outdoors: Feb 14 – Feb 21 |
| Eggplant | Start seeds indoors: Nov 22 – Dec 6 Transplant outdoors: Feb 14 – Feb 21 |
| Broccoli | Start seeds indoors: Nov 22 – Dec 6 Transplant outdoors: Jan 3 – Jan 17 |
| Cabbage | Start seeds indoors: Nov 22 – Dec 6 Transplant outdoors: Jan 3 – Jan 17 |
| Onions (sets) | Plant outdoors: Jan 3 – Jan 17 |
| Peas | Sow outdoors: Dec 20 – Jan 3 |
| Spinach | Sow outdoors: Dec 20 – Jan 3 |
| Lettuce | Sow outdoors: Jan 3 – Jan 17 |
| Carrots | Sow outdoors: Jan 3 – Jan 17 |
| Potatoes | Plant outdoors: Jan 3 – Jan 17 |
| Beans | Sow outdoors: Feb 7 – Feb 14 |
| Sweet corn | Sow outdoors: Feb 7 – Feb 14 |
| Cucumbers | Sow outdoors: Feb 7 – Feb 14 |
| Squash & zucchini | Sow outdoors: Feb 7 – Feb 14 |
| Basil | Start seeds indoors: Dec 20 – Jan 3 Transplant outdoors: Feb 7 – Feb 14 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 15 (8 weeks before the average first fall frost on Dec 10).
Useful for zone 9b gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Dec 31 | Jan 31 | Feb 28 |
| First 32°F frost in fall is before | Jan 6 | Dec 10 | Nov 22 |
How to read it: in spring there is a 10% chance of a frost after February 28, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 22. A hard freeze (28°F) usually ends around January 3.
Hardiness zone by ZIP code in San Jacinto
- 92581 zone 9b
- 92582 zone 9b
- 92583 zone 9b
Nearby cities
- Hemet zone 9b, last frost Jan 31
- East Hemet zone 9b, last frost Jan 10
- Valle Vista zone 9b, last frost Jan 10
- Beaumont zone 9b, last frost Jan 10
- Banning zone 9b, last frost Jan 31
- Menifee zone 9b, last frost Jan 31
- Yucaipa zone 9b, last frost Jan 10
- Perris zone 9b, last frost Jan 28
Questions
What growing zone is San Jacinto, CA?
San Jacinto is in USDA Plant Hardiness Zone 9b (average extreme winter low 25°F to 30°F), according to the USDA 2023 map.
When is the last frost in San Jacinto?
The average last spring frost (32°F) in San Jacinto is January 31. There is still a 10% chance of frost until February 28.
When can I plant tomatoes in San Jacinto?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Feb 7 – Feb 14. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station San Jacinto, CA (USC00047813), 2.1 km (1.3 mi) from the city center, elevation 465 m, based on 26 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.