Fort Thomas, AZ frost dates
Last spring frostApr 1median date
First fall frostNov 6median date
Growing season219 daysfrost-free
Hardiness zone8bZone 8b
How Fort Thomas compares
- In 8 years out of 10, the last spring frost in Fort Thomas falls between March 15 and April 18, a 34-day window. The first fall frost falls between October 21 and November 19.
- The median last frost is 15 days earlier than the Arizona median of Apr 16.
- Its 219-day growing season is longer than 59% of the 193 Arizona places with a regular frost season (state median 197 days).
- The last frost is 16 days later than the zone 8b median of Mar 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 8b chart.
- The weather station records an average of 82 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 15 |
| 50% (median) | April 1 |
| 10% (safe for tender plants) | April 18 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 21 |
| 50% (median) | November 6 |
| 90% (late) | November 19 |
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 Fort Thomas, AZ
Fort Thomas, AZ frost dates — last frost Apr 1, first frost Nov 6, zone 8b. whenisthelastfrost.com
Crop
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Start indoors: Jan 7 to Jan 21Transplant outside: Mar 4 to Mar 18
Start indoors: Jan 21 to Feb 4Transplant outside: Apr 15 to Apr 29
Start indoors: Jan 21 to Feb 4Transplant outside: Apr 15 to Apr 29
Start indoors: Feb 4 to Feb 18Transplant outside: Apr 8 to Apr 22
Start indoors: Feb 4 to Feb 18Transplant outside: Mar 11 to Mar 25Sow outdoors: Mar 4 to Apr 8Plant for fall: Sep 11 to Oct 9
Start indoors: Feb 4 to Feb 18Transplant outside: Mar 4 to Mar 18Sow outdoors: Mar 4 to Mar 18Plant for fall: Aug 28 to Sep 18
Start indoors: Feb 4 to Feb 18Transplant outside: Mar 18 to Apr 1Plant for fall: Jul 31 to Aug 21
Start indoors: Feb 4 to Feb 18Transplant outside: Mar 11 to Mar 25Plant for fall: Jul 31 to Aug 21
Start indoors: Feb 4 to Feb 18Transplant outside: Mar 18 to Apr 1Plant for fall: Jul 31 to Aug 21
Start indoors: Feb 18 to Mar 4Transplant outside: Apr 22 to May 6Sow outdoors: Apr 22 to May 6
Start indoors: Feb 18 to Mar 4Transplant outside: Apr 8 to Apr 22
Sow outdoors: Feb 18 to Mar 11Plant for fall: Aug 14 to Sep 4
Sow outdoors: Feb 18 to Mar 11Plant for fall: Sep 11 to Oct 2
Sow outdoors: Feb 25 to Apr 8Plant for fall: Sep 25 to Oct 16
Start indoors: Mar 4 to Mar 11Transplant outside: Apr 15 to Apr 22Sow outdoors: Apr 8 to Apr 22Plant for fall: Aug 21 to Sep 4
Start indoors: Mar 4 to Mar 11Sow outdoors: Apr 8 to Apr 22Plant for fall: Aug 28 to Sep 11
Start indoors: Mar 4 to Mar 11Sow outdoors: Apr 8 to Apr 22
Start indoors: Mar 4 to Mar 11Transplant outside: Apr 15 to Apr 29
Sow outdoors: Mar 11 to Apr 8Plant for fall: Aug 14 to Aug 28
Sow outdoors: Mar 11 to Apr 8Plant for fall: Aug 28 to Sep 11
Sow outdoors: Mar 11 to Apr 1
Sow outdoors: Mar 18 to Apr 15Plant for fall: Aug 28 to Sep 11
Sow outdoors: Mar 18 to Apr 8Plant for fall: Sep 11 to Oct 2
Sow outdoors: Apr 8 to Apr 29Plant for fall: Aug 21 to Sep 4
Sow outdoors: Apr 8 to Apr 22
Transplant outside: Apr 15 to May 6
Plant for fall: Oct 23 to Nov 27
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Fort Thomas, AZ
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 7 – Jan 21 | Mar 4 – Mar 18 | — | — |
| Peppers | Jan 21 – Feb 4 | Apr 15 – Apr 29 | — | — |
| Eggplant | Jan 21 – Feb 4 | Apr 15 – Apr 29 | — | — |
| Tomatoes | Feb 4 – Feb 18 | Apr 8 – Apr 22 | — | — |
| Lettuce | Feb 4 – Feb 18 | Mar 11 – Mar 25 | Mar 4 – Apr 8 | Sep 11 – Oct 9 |
| Kale | Feb 4 – Feb 18 | Mar 4 – Mar 18 | Mar 4 – Mar 18 | Aug 28 – Sep 18 |
| Broccoli | Feb 4 – Feb 18 | Mar 18 – Apr 1 | — | Jul 31 – Aug 21 |
| Cabbage | Feb 4 – Feb 18 | Mar 11 – Mar 25 | — | Jul 31 – Aug 21 |
| Cauliflower | Feb 4 – Feb 18 | Mar 18 – Apr 1 | — | Jul 31 – Aug 21 |
| Okra | Feb 18 – Mar 4 | Apr 22 – May 6 | Apr 22 – May 6 | — |
| Basil | Feb 18 – Mar 4 | Apr 8 – Apr 22 | — | — |
| Peas | — | — | Feb 18 – Mar 11 | Aug 14 – Sep 4 |
| Spinach | — | — | Feb 18 – Mar 11 | Sep 11 – Oct 2 |
| Radishes | — | — | Feb 25 – Apr 8 | Sep 25 – Oct 16 |
| Cucumbers | Mar 4 – Mar 11 | Apr 15 – Apr 22 | Apr 8 – Apr 22 | Aug 21 – Sep 4 |
| Zucchini & Summer Squash | Mar 4 – Mar 11 | — | Apr 8 – Apr 22 | Aug 28 – Sep 11 |
| Winter Squash & Pumpkins | Mar 4 – Mar 11 | — | Apr 8 – Apr 22 | — |
| Melons & Watermelon | Mar 4 – Mar 11 | Apr 15 – Apr 29 | — | — |
| Carrots | — | — | Mar 11 – Apr 8 | Aug 14 – Aug 28 |
| Beets | — | — | Mar 11 – Apr 8 | Aug 28 – Sep 11 |
| Potatoes | — | — | Mar 11 – Apr 1 | — |
| Swiss Chard | — | — | Mar 18 – Apr 15 | Aug 28 – Sep 11 |
| Cilantro | — | — | Mar 18 – Apr 8 | Sep 11 – Oct 2 |
| Green Beans | — | — | Apr 8 – Apr 29 | Aug 21 – Sep 4 |
| Sweet Corn | — | — | Apr 8 – Apr 22 | — |
| Sweet Potatoes | — | Apr 15 – May 6 | — | — |
| Garlic | — | — | — | Oct 23 – Nov 27 |
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 Ft Thomas 2 Sw, AZ weather station, 3 km away (elevation 2,835 ft (864 m)).
Frost dates near Fort Thomas
- Eden Apr 1 · Nov 6
- Bylas Apr 1 · Nov 6
- Pima Apr 1 · Nov 6
- Central Mar 25 · Nov 9
- Thatcher Mar 25 · Nov 9
- Safford Mar 25 · Nov 9
- Solomon Mar 25 · Nov 9
- Peridot Mar 13 · Nov 19
- Morenci Feb 26 · Nov 23
- San Carlos Mar 13 · Nov 19
Frequently asked questions
When is the last frost in Fort Thomas, AZ?
The median last spring frost in Fort Thomas, AZ is April 1. There is still about a 10% chance of frost after April 18, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Fort Thomas, AZ?
The median first fall frost is November 6, with about a 10% chance of frost before October 21.
How long is the growing season in Fort Thomas, AZ?
About 219 days between the median last spring frost and first fall frost.
What planting zone is Fort Thomas, AZ?
Fort Thomas, AZ is in USDA hardiness zone 8b.