Norco, CA frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 11 a year). Cover tender plants when frost is forecast.
How Norco compares
- In a typical year, frost nights in Norco fall between December 19 and January 17. In 1 year in 10 the first frost comes as early as November 27, or the last frost as late as February 22.
- Compared with Corona, CA, 8 km away, the last frost here is 8 days later than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 18 |
| 50% (median) | January 17 |
| 10% (safe for tender plants) | February 22 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 27 |
| 50% (median) | December 19 |
| 90% (late) | January 17 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Gardening where frost is rare
Norco, CA only freezes on a few winter nights, so the usual "plant after the last frost" rule doesn't apply. Heat and rainfall decide the seasons instead:
- Cool-season crops (lettuce, broccoli, peas, carrots) grow best from fall through late winter.
- Warm-season crops (tomatoes, peppers, beans, squash) do best planted in late winter to spring, and again in late summer for a fall crop — midsummer heat can stop tomatoes setting fruit.
- Heat lovers (okra, sweet potatoes, melons) can be planted through spring and early summer.
About these dates
Based on 1991–2020 NOAA climate normals for the Chino Ap, CA weather station, 10 km away (elevation 650 ft (198 m)).
Frost dates near Norco
- Corona Jan 9 · Dec 30
- Mira Loma Jan 9 · Dec 30
- Chino Jan 17 · Dec 19
- Riverside Jan 9 · Dec 25
- March Air Reserve Base Jan 9 · Dec 25
- Guasti Jan 4 · Dec 30
- Ontario Jan 4 · Dec 30
- Chino Hills Jan 17 · Dec 19
- Fontana Jan 4 · Dec 30
- Silverado rare frost
Frequently asked questions
When is the last frost in Norco, CA?
The median last spring frost in Norco, CA is January 17. There is still about a 10% chance of frost after February 22, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Norco, CA?
The median first fall frost is December 19, with about a 10% chance of frost before November 27.
How long is the growing season in Norco, CA?
About 336 days between the median last spring frost and first fall frost.
What planting zone is Norco, CA?
Norco, CA is in USDA hardiness zone 10a.