New River, AZ 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 New River compares
- In a typical year, frost nights in New River fall between December 22 and January 15. In 1 year in 10 the first frost comes as early as November 29, or the last frost as late as February 21.
- Compared with Peoria, AZ, 35 km away, the last frost here is 5 days earlier than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 19 |
| 50% (median) | January 15 |
| 10% (safe for tender plants) | February 21 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 29 |
| 50% (median) | December 22 |
| 90% (late) | January 26 |
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
New River, AZ 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 Castle Hot Springs, AZ weather station, 23 km away (elevation 1,991 ft (607 m)).
Frost dates near New River
- Black Canyon City Jan 15 · Dec 22
- Cave Creek Feb 4 · Dec 16
- Carefree Feb 4 · Dec 16
- Sun City West Jan 20 · Dec 15
- Peoria Jan 20 · Dec 15
- Sun City Jan 20 · Dec 15
- Crown King Apr 5 · Nov 17
- Glendale Jan 20 · Dec 15
- El Mirage Jan 20 · Dec 15
- Surprise Jan 20 · Dec 15
Frequently asked questions
When is the last frost in New River, AZ?
The median last spring frost in New River, AZ is January 15. 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 New River, AZ?
The median first fall frost is December 22, with about a 10% chance of frost before November 29.
How long is the growing season in New River, AZ?
About 341 days between the median last spring frost and first fall frost.
What planting zone is New River, AZ?
New River, AZ is in USDA hardiness zone 9b.