Oroville, CA planting zone & frost dates
Oroville is in USDA hardiness zone 9b. The last spring frost usually comes around January 30 and the first fall frost around December 13, for a growing season of about 321 days.
Planting calendar for Oroville
Dates are counted from the average last spring frost (January 30) 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 5 – Dec 19 Transplant outdoors: Feb 6 – Feb 13 |
| Peppers | Start seeds indoors: Nov 21 – Dec 5 Transplant outdoors: Feb 13 – Feb 20 |
| Eggplant | Start seeds indoors: Nov 21 – Dec 5 Transplant outdoors: Feb 13 – Feb 20 |
| Broccoli | Start seeds indoors: Nov 21 – Dec 5 Transplant outdoors: Jan 2 – Jan 16 |
| Cabbage | Start seeds indoors: Nov 21 – Dec 5 Transplant outdoors: Jan 2 – Jan 16 |
| Onions (sets) | Plant outdoors: Jan 2 – Jan 16 |
| Peas | Sow outdoors: Dec 19 – Jan 2 |
| Spinach | Sow outdoors: Dec 19 – Jan 2 |
| Lettuce | Sow outdoors: Jan 2 – Jan 16 |
| Carrots | Sow outdoors: Jan 2 – Jan 16 |
| Potatoes | Plant outdoors: Jan 2 – Jan 16 |
| Beans | Sow outdoors: Feb 6 – Feb 13 |
| Sweet corn | Sow outdoors: Feb 6 – Feb 13 |
| Cucumbers | Sow outdoors: Feb 6 – Feb 13 |
| Squash & zucchini | Sow outdoors: Feb 6 – Feb 13 |
| Basil | Start seeds indoors: Dec 19 – Jan 2 Transplant outdoors: Feb 6 – Feb 13 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 18 (8 weeks before the average first fall frost on Dec 13).
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 26 | Jan 30 | Mar 3 |
| First 32°F frost in fall is before | Jan 11 | Dec 13 | Nov 21 |
How to read it: in spring there is a 10% chance of a frost after March 3, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 21. A hard freeze (28°F) usually ends around January 5.
Hardiness zone by ZIP code in Oroville
- 95965 zone 9b
- 95966 zone 9b
Nearby cities
- Paradise zone 9b, last frost Feb 7
- Magalia zone 8b, last frost Apr 17
- Chico zone 9a, last frost Mar 4
- Marysville zone 9b, last frost Jan 15
- Yuba City zone 9b, last frost Jan 15
- Linda zone 9b, last frost Feb 11
- South Yuba City zone 9b, last frost Jan 15
- Olivehurst zone 9b, last frost Feb 11
Questions
What growing zone is Oroville, CA?
Oroville 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 Oroville?
The average last spring frost (32°F) in Oroville is January 30. There is still a 10% chance of frost until March 3.
When can I plant tomatoes in Oroville?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Feb 6 – Feb 13. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Oroville, CA (USC00046521), 0.6 km (0.4 mi) from the city center, elevation 52 m, based on 19 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.