Mammoth, AZ frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 14 a year). Cover tender plants when frost is forecast.
How Mammoth compares
- In a typical year, frost nights in Mammoth fall between December 8 and February 4. In 1 year in 10 the first frost comes as early as November 20, or the last frost as late as March 2.
- Compared with Tucson, AZ, 62 km away, the last frost here is 15 days later than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | January 5 |
| 50% (median) | February 4 |
| 10% (safe for tender plants) | March 2 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 20 |
| 50% (median) | December 8 |
| 90% (late) | December 28 |
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 Mammoth, AZ
Mammoth, AZ frost dates — last frost Feb 4, first frost Dec 8, 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 Mammoth, AZ
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Nov 12 – Nov 26 | Jan 7 – Jan 21 | — | — |
| Peppers | Nov 26 – Dec 10 | Feb 18 – Mar 4 | — | — |
| Eggplant | Nov 26 – Dec 10 | Feb 18 – Mar 4 | — | — |
| Tomatoes | Dec 10 – Dec 24 | Feb 11 – Feb 25 | — | — |
| Lettuce | Dec 10 – Dec 24 | Jan 14 – Jan 28 | Jan 7 – Feb 11 | Oct 13 – Nov 10 |
| Kale | Dec 10 – Dec 24 | Jan 7 – Jan 21 | Jan 7 – Jan 21 | Sep 29 – Oct 20 |
| Broccoli | Dec 10 – Dec 24 | Jan 21 – Feb 4 | — | Sep 1 – Sep 22 |
| Cabbage | Dec 10 – Dec 24 | Jan 14 – Jan 28 | — | Sep 1 – Sep 22 |
| Cauliflower | Dec 10 – Dec 24 | Jan 21 – Feb 4 | — | Sep 1 – Sep 22 |
| Okra | Dec 24 – Jan 7 | Feb 25 – Mar 11 | Feb 25 – Mar 11 | — |
| Basil | Dec 24 – Jan 7 | Feb 11 – Feb 25 | — | — |
| Peas | — | — | Dec 24 – Jan 14 | Sep 15 – Oct 6 |
| Spinach | — | — | Dec 24 – Jan 14 | Oct 13 – Nov 3 |
| Radishes | — | — | Dec 31 – Feb 11 | Oct 27 – Nov 17 |
| Cucumbers | Jan 7 – Jan 14 | Feb 18 – Feb 25 | Feb 11 – Feb 25 | Sep 22 – Oct 6 |
| Zucchini & Summer Squash | Jan 7 – Jan 14 | — | Feb 11 – Feb 25 | Sep 29 – Oct 13 |
| Winter Squash & Pumpkins | Jan 7 – Jan 14 | — | Feb 11 – Feb 25 | — |
| Melons & Watermelon | Jan 7 – Jan 14 | Feb 18 – Mar 4 | — | — |
| Carrots | — | — | Jan 14 – Feb 11 | Sep 15 – Sep 29 |
| Beets | — | — | Jan 14 – Feb 11 | Sep 29 – Oct 13 |
| Potatoes | — | — | Jan 14 – Feb 4 | — |
| Swiss Chard | — | — | Jan 21 – Feb 18 | Sep 29 – Oct 13 |
| Cilantro | — | — | Jan 21 – Feb 11 | Oct 13 – Nov 3 |
| Green Beans | — | — | Feb 11 – Mar 4 | Sep 22 – Oct 6 |
| Sweet Corn | — | — | Feb 11 – Feb 25 | — |
| Sweet Potatoes | — | Feb 18 – Mar 11 | — | — |
| Garlic | — | — | — | Nov 24 – Dec 29 |
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 San Manuel, AZ weather station, 14 km away (elevation 3,419 ft (1,042 m)).
Frost dates near Mammoth
- San Manuel Feb 4 · Dec 8
- Oracle Mar 23 · Nov 22
- Winkelman Mar 13 · Nov 19
- Hayden Mar 13 · Nov 19
- Catalina Apr 2 · Nov 11
- Mount Lemmon Apr 1 · Nov 19
- Kearny Jan 18 · Dec 28
- Cortaro Feb 26 · Dec 4
- Rillito Feb 23 · Dec 6
- Tucson Jan 20 · Dec 17
Frequently asked questions
When is the last frost in Mammoth, AZ?
The median last spring frost in Mammoth, AZ is February 4. There is still about a 10% chance of frost after March 2, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Mammoth, AZ?
The median first fall frost is December 8, with about a 10% chance of frost before November 20.
How long is the growing season in Mammoth, AZ?
About 307 days between the median last spring frost and first fall frost.
What planting zone is Mammoth, AZ?
Mammoth, AZ is in USDA hardiness zone 9a.