Superior, AZ frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 3 a year). Cover tender plants when frost is forecast.
How Superior compares
- In a typical year, frost nights in Superior fall between December 28 and January 18. In 1 year in 10 the first frost comes as early as December 1, or the last frost as late as March 1.
- Compared with San Tan Valley, AZ, 41 km away, the last frost here is 14 days earlier than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 19 |
| 50% (median) | January 18 |
| 10% (safe for tender plants) | March 1 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | December 1 |
| 50% (median) | December 28 |
| 90% (late) | February 1 |
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
Superior, 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 Superior, AZ weather station, about 1 km away (elevation 2,861 ft (872 m)).
Frost dates near Superior
- Gold Canyon Feb 11 · Dec 10
- Miami Feb 24 · Dec 1
- Claypool Mar 11 · Nov 21
- Kearny Jan 18 · Dec 28
- Globe Mar 11 · Nov 21
- Apache Junction Feb 11 · Dec 10
- Tortilla Flat Jan 29 · Dec 24
- Roosevelt Jan 17 · Dec 25
- Florence Jan 30 · Dec 12
- San Tan Valley Feb 1 · Dec 11
Frequently asked questions
When is the last frost in Superior, AZ?
The median last spring frost in Superior, AZ is January 18. There is still about a 10% chance of frost after March 1, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Superior, AZ?
The median first fall frost is December 28, with about a 10% chance of frost before December 1.
How long is the growing season in Superior, AZ?
About 344 days between the median last spring frost and first fall frost.
What planting zone is Superior, AZ?
Superior, AZ is in USDA hardiness zone 9b.