Mira Loma, CA frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 4 a year). Cover tender plants when frost is forecast.
How Mira Loma compares
- In a typical year, frost nights in Mira Loma fall between December 30 and January 9. In 1 year in 10 the first frost comes as early as December 5, or the last frost as late as February 21.
- Compared with Fontana, CA, 12 km away, the last frost here is 5 days later than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 16 |
| 50% (median) | January 9 |
| 10% (safe for tender plants) | February 21 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | December 5 |
| 50% (median) | December 30 |
| 90% (late) | February 6 |
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
Mira Loma, 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 Riverside Muni Ap, CA weather station, 9 km away (elevation 804 ft (245 m)).
Frost dates near Mira Loma
- Norco Jan 17 · Dec 19
- Guasti Jan 4 · Dec 30
- Fontana Jan 4 · Dec 30
- Riverside Jan 9 · Dec 25
- March Air Reserve Base Jan 9 · Dec 25
- Ontario Jan 4 · Dec 30
- Chino Jan 17 · Dec 19
- Bloomington Jan 10 · Jan 2
- Corona Jan 9 · Dec 30
- Rancho Cucamonga Jan 4 · Dec 30
Frequently asked questions
When is the last frost in Mira Loma, CA?
The median last spring frost in Mira Loma, CA is January 9. There is still about a 10% chance of frost after February 21, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Mira Loma, CA?
The median first fall frost is December 30, with about a 10% chance of frost before December 5.
How long is the growing season in Mira Loma, CA?
About 355 days between the median last spring frost and first fall frost.
What planting zone is Mira Loma, CA?
Mira Loma, CA is in USDA hardiness zone 10a.