Red Rock, AZ frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 10 a year). Cover tender plants when frost is forecast.
How Red Rock compares
- In a typical year, frost nights in Red Rock fall between December 9 and February 6. In 1 year in 10 the first frost comes as early as November 22, or the last frost as late as March 5.
- Compared with Casa Grande, AZ, 48 km away, the last frost here is 1 day later than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | January 6 |
| 50% (median) | February 6 |
| 10% (safe for tender plants) | March 5 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 22 |
| 50% (median) | December 9 |
| 90% (late) | December 26 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Red Rock, AZ
Red Rock, AZ frost dates — last frost Feb 6, first frost Dec 9, zone 9a. whenisthelastfrost.com
In mild climates, summer heat limits many crops as much as frost does. Use this calendar for spring planting and lean on fall and winter for cool-season crops.
When to plant vegetables in Red Rock, AZ
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Nov 14 – Nov 28 | Jan 9 – Jan 23 | — | — |
| Peppers | Nov 28 – Dec 12 | Feb 20 – Mar 6 | — | — |
| Eggplant | Nov 28 – Dec 12 | Feb 20 – Mar 6 | — | — |
| Tomatoes | Dec 12 – Dec 26 | Feb 13 – Feb 27 | — | — |
| Lettuce | Dec 12 – Dec 26 | Jan 16 – Jan 30 | Jan 9 – Feb 13 | Oct 14 – Nov 11 |
| Kale | Dec 12 – Dec 26 | Jan 9 – Jan 23 | Jan 9 – Jan 23 | Sep 30 – Oct 21 |
| Broccoli | Dec 12 – Dec 26 | Jan 23 – Feb 6 | — | Sep 2 – Sep 23 |
| Cabbage | Dec 12 – Dec 26 | Jan 16 – Jan 30 | — | Sep 2 – Sep 23 |
| Cauliflower | Dec 12 – Dec 26 | Jan 23 – Feb 6 | — | Sep 2 – Sep 23 |
| Okra | Dec 26 – Jan 9 | Feb 27 – Mar 13 | Feb 27 – Mar 13 | — |
| Basil | Dec 26 – Jan 9 | Feb 13 – Feb 27 | — | — |
| Peas | — | — | Dec 26 – Jan 16 | Sep 16 – Oct 7 |
| Spinach | — | — | Dec 26 – Jan 16 | Oct 14 – Nov 4 |
| Radishes | — | — | Jan 2 – Feb 13 | Oct 28 – Nov 18 |
| Cucumbers | Jan 9 – Jan 16 | Feb 20 – Feb 27 | Feb 13 – Feb 27 | Sep 23 – Oct 7 |
| Zucchini & Summer Squash | Jan 9 – Jan 16 | — | Feb 13 – Feb 27 | Sep 30 – Oct 14 |
| Winter Squash & Pumpkins | Jan 9 – Jan 16 | — | Feb 13 – Feb 27 | — |
| Melons & Watermelon | Jan 9 – Jan 16 | Feb 20 – Mar 6 | — | — |
| Carrots | — | — | Jan 16 – Feb 13 | Sep 16 – Sep 30 |
| Beets | — | — | Jan 16 – Feb 13 | Sep 30 – Oct 14 |
| Potatoes | — | — | Jan 16 – Feb 6 | — |
| Swiss Chard | — | — | Jan 23 – Feb 20 | Sep 30 – Oct 14 |
| Cilantro | — | — | Jan 23 – Feb 13 | Oct 14 – Nov 4 |
| Green Beans | — | — | Feb 13 – Mar 6 | Sep 23 – Oct 7 |
| Sweet Corn | — | — | Feb 13 – Feb 27 | — |
| Sweet Potatoes | — | Feb 20 – Mar 13 | — | — |
| Garlic | — | — | — | Nov 25 – Dec 30 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Picacho 8 Se, AZ weather station, 9 km away (elevation 1,982 ft (604 m)).
Frost dates near Red Rock
- Picacho Feb 6 · Dec 9
- Marana Feb 23 · Dec 6
- Rillito Feb 23 · Dec 6
- Cortaro Feb 26 · Dec 4
- Eloy Feb 24 · Nov 28
- Arizona City Feb 28 · Nov 21
- Catalina Apr 2 · Nov 11
- Coolidge Feb 17 · Nov 29
- Valley Farms Jan 30 · Dec 12
- Florence Jan 30 · Dec 12
Frequently asked questions
When is the last frost in Red Rock, AZ?
The median last spring frost in Red Rock, AZ is February 6. There is still about a 10% chance of frost after March 5, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Red Rock, AZ?
The median first fall frost is December 9, with about a 10% chance of frost before November 22.
How long is the growing season in Red Rock, AZ?
About 306 days between the median last spring frost and first fall frost.
What planting zone is Red Rock, AZ?
Red Rock, AZ is in USDA hardiness zone 9a.