Fort Supply, OK frost dates
Last spring frostApr 21median date
First fall frostOct 19median date
Growing season181 daysfrost-free
Hardiness zone7aZone 7a
How Fort Supply compares
- In 8 years out of 10, the last spring frost in Fort Supply falls between April 8 and May 5, a 27-day window. The first fall frost falls between October 4 and October 31.
- The median last frost is 17 days later than the Oklahoma median of Apr 4.
- Its 181-day growing season is among the shortest of the 582 Oklahoma places with a regular frost season.
- The last frost is 5 days later than the zone 7a median of Apr 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7a chart.
- The weather station records an average of 124 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 8 |
| 50% (median) | April 21 |
| 10% (safe for tender plants) | May 5 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 4 |
| 50% (median) | October 19 |
| 90% (late) | October 31 |
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 Supply, OK
Fort Supply, OK frost dates — last frost Apr 21, first frost Oct 19, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Jan 27 to Feb 10Transplant outside: Mar 24 to Apr 7
Start indoors: Feb 10 to Feb 24Transplant outside: May 5 to May 19
Start indoors: Feb 10 to Feb 24Transplant outside: May 5 to May 19
Start indoors: Feb 24 to Mar 10Transplant outside: Apr 28 to May 12
Start indoors: Feb 24 to Mar 10Transplant outside: Mar 31 to Apr 14Sow outdoors: Mar 24 to Apr 28Plant for fall: Aug 24 to Sep 21
Start indoors: Feb 24 to Mar 10Transplant outside: Mar 24 to Apr 7Sow outdoors: Mar 24 to Apr 7Plant for fall: Aug 10 to Aug 31
Start indoors: Feb 24 to Mar 10Transplant outside: Apr 7 to Apr 21Plant for fall: Jul 13 to Aug 3
Start indoors: Feb 24 to Mar 10Transplant outside: Mar 31 to Apr 14Plant for fall: Jul 13 to Aug 3
Start indoors: Feb 24 to Mar 10Transplant outside: Apr 7 to Apr 21Plant for fall: Jul 13 to Aug 3
Start indoors: Mar 10 to Mar 24Transplant outside: May 12 to May 26Sow outdoors: May 12 to May 26
Start indoors: Mar 10 to Mar 24Transplant outside: Apr 28 to May 12
Sow outdoors: Mar 10 to Mar 31Plant for fall: Jul 27 to Aug 17
Sow outdoors: Mar 10 to Mar 31Plant for fall: Aug 24 to Sep 14
Sow outdoors: Mar 17 to Apr 28Plant for fall: Sep 7 to Sep 28
Start indoors: Mar 24 to Mar 31Transplant outside: May 5 to May 12Sow outdoors: Apr 28 to May 12Plant for fall: Aug 3 to Aug 17
Start indoors: Mar 24 to Mar 31Sow outdoors: Apr 28 to May 12Plant for fall: Aug 10 to Aug 24
Start indoors: Mar 24 to Mar 31Sow outdoors: Apr 28 to May 12
Start indoors: Mar 24 to Mar 31Transplant outside: May 5 to May 19
Sow outdoors: Mar 31 to Apr 28Plant for fall: Jul 27 to Aug 10
Sow outdoors: Mar 31 to Apr 28Plant for fall: Aug 10 to Aug 24
Sow outdoors: Mar 31 to Apr 21
Sow outdoors: Apr 7 to May 5Plant for fall: Aug 10 to Aug 24
Sow outdoors: Apr 7 to Apr 28Plant for fall: Aug 24 to Sep 14
Sow outdoors: Apr 28 to May 19Plant for fall: Aug 3 to Aug 17
Sow outdoors: Apr 28 to May 12
Transplant outside: May 5 to May 26
Plant for fall: Oct 5 to Nov 9
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Fort Supply, OK
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 27 – Feb 10 | Mar 24 – Apr 7 | — | — |
| Peppers | Feb 10 – Feb 24 | May 5 – May 19 | — | — |
| Eggplant | Feb 10 – Feb 24 | May 5 – May 19 | — | — |
| Tomatoes | Feb 24 – Mar 10 | Apr 28 – May 12 | — | — |
| Lettuce | Feb 24 – Mar 10 | Mar 31 – Apr 14 | Mar 24 – Apr 28 | Aug 24 – Sep 21 |
| Kale | Feb 24 – Mar 10 | Mar 24 – Apr 7 | Mar 24 – Apr 7 | Aug 10 – Aug 31 |
| Broccoli | Feb 24 – Mar 10 | Apr 7 – Apr 21 | — | Jul 13 – Aug 3 |
| Cabbage | Feb 24 – Mar 10 | Mar 31 – Apr 14 | — | Jul 13 – Aug 3 |
| Cauliflower | Feb 24 – Mar 10 | Apr 7 – Apr 21 | — | Jul 13 – Aug 3 |
| Okra | Mar 10 – Mar 24 | May 12 – May 26 | May 12 – May 26 | — |
| Basil | Mar 10 – Mar 24 | Apr 28 – May 12 | — | — |
| Peas | — | — | Mar 10 – Mar 31 | Jul 27 – Aug 17 |
| Spinach | — | — | Mar 10 – Mar 31 | Aug 24 – Sep 14 |
| Radishes | — | — | Mar 17 – Apr 28 | Sep 7 – Sep 28 |
| Cucumbers | Mar 24 – Mar 31 | May 5 – May 12 | Apr 28 – May 12 | Aug 3 – Aug 17 |
| Zucchini & Summer Squash | Mar 24 – Mar 31 | — | Apr 28 – May 12 | Aug 10 – Aug 24 |
| Winter Squash & Pumpkins | Mar 24 – Mar 31 | — | Apr 28 – May 12 | — |
| Melons & Watermelon | Mar 24 – Mar 31 | May 5 – May 19 | — | — |
| Carrots | — | — | Mar 31 – Apr 28 | Jul 27 – Aug 10 |
| Beets | — | — | Mar 31 – Apr 28 | Aug 10 – Aug 24 |
| Potatoes | — | — | Mar 31 – Apr 21 | — |
| Swiss Chard | — | — | Apr 7 – May 5 | Aug 10 – Aug 24 |
| Cilantro | — | — | Apr 7 – Apr 28 | Aug 24 – Sep 14 |
| Green Beans | — | — | Apr 28 – May 19 | Aug 3 – Aug 17 |
| Sweet Corn | — | — | Apr 28 – May 12 | — |
| Sweet Potatoes | — | May 5 – May 26 | — | — |
| Garlic | — | — | — | Oct 5 – Nov 9 |
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 Supply 3se, OK weather station, 5 km away (elevation 2,031 ft (619 m)).
Frost dates near Fort Supply
- May Apr 17 · Oct 23
- Woodward Apr 5 · Oct 30
- Fargo Apr 17 · Oct 20
- Buffalo Apr 13 · Oct 25
- Laverne Apr 13 · Oct 28
- Gage Apr 17 · Oct 20
- Mooreland Apr 5 · Oct 30
- Sharon Apr 19 · Oct 26
- Shattuck Apr 17 · Oct 20
- Rosston Apr 13 · Oct 28
Frequently asked questions
When is the last frost in Fort Supply, OK?
The median last spring frost in Fort Supply, OK is April 21. There is still about a 10% chance of frost after May 5, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Fort Supply, OK?
The median first fall frost is October 19, with about a 10% chance of frost before October 4.
How long is the growing season in Fort Supply, OK?
About 181 days between the median last spring frost and first fall frost.
What planting zone is Fort Supply, OK?
Fort Supply, OK is in USDA hardiness zone 7a.