Frost dates for 73521 — Altus, OK
Last spring frostApr 5median date
First fall frostNov 2median date
Growing season211 daysfrost-free
Hardiness zone7bZone 7b
How Altus compares
- In 8 years out of 10, the last spring frost in Altus falls between March 20 and April 21, a 32-day window. The first fall frost falls between October 19 and November 16.
- The median last frost is 1 day later than the Oklahoma median of Apr 4.
- Its 211-day growing season is longer than 48% of the 582 Oklahoma places with a regular frost season (state median 211 days).
- The last frost is typical for zone 7b, where the median is Apr 5.
- The weather station records an average of 86 nights a year at or below 32°F.
- Compared with Lawton, OK, 83 km away, the last frost here is 10 days later than there and the growing season is 15 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 20 |
| 50% (median) | April 5 |
| 10% (safe for tender plants) | April 21 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 19 |
| 50% (median) | November 2 |
| 90% (late) | November 16 |
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 Altus, OK
Frost dates for 73521 — Altus, OK — last frost Apr 5, first frost Nov 2, zone 7b. whenisthelastfrost.com
Crop
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Start indoors: Jan 11 to Jan 25Transplant outside: Mar 8 to Mar 22
Start indoors: Jan 25 to Feb 8Transplant outside: Apr 19 to May 3
Start indoors: Jan 25 to Feb 8Transplant outside: Apr 19 to May 3
Start indoors: Feb 8 to Feb 22Transplant outside: Apr 12 to Apr 26
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 15 to Mar 29Sow outdoors: Mar 8 to Apr 12Plant for fall: Sep 7 to Oct 5
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 8 to Mar 22Sow outdoors: Mar 8 to Mar 22Plant for fall: Aug 24 to Sep 14
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 22 to Apr 5Plant for fall: Jul 27 to Aug 17
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 15 to Mar 29Plant for fall: Jul 27 to Aug 17
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 22 to Apr 5Plant for fall: Jul 27 to Aug 17
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 26 to May 10Sow outdoors: Apr 26 to May 10
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 12 to Apr 26
Sow outdoors: Feb 22 to Mar 15Plant for fall: Aug 10 to Aug 31
Sow outdoors: Feb 22 to Mar 15Plant for fall: Sep 7 to Sep 28
Sow outdoors: Mar 1 to Apr 12Plant for fall: Sep 21 to Oct 12
Start indoors: Mar 8 to Mar 15Transplant outside: Apr 19 to Apr 26Sow outdoors: Apr 12 to Apr 26Plant for fall: Aug 17 to Aug 31
Start indoors: Mar 8 to Mar 15Sow outdoors: Apr 12 to Apr 26Plant for fall: Aug 24 to Sep 7
Start indoors: Mar 8 to Mar 15Sow outdoors: Apr 12 to Apr 26
Start indoors: Mar 8 to Mar 15Transplant outside: Apr 19 to May 3
Sow outdoors: Mar 15 to Apr 12Plant for fall: Aug 10 to Aug 24
Sow outdoors: Mar 15 to Apr 12Plant for fall: Aug 24 to Sep 7
Sow outdoors: Mar 15 to Apr 5
Sow outdoors: Mar 22 to Apr 19Plant for fall: Aug 24 to Sep 7
Sow outdoors: Mar 22 to Apr 12Plant for fall: Sep 7 to Sep 28
Sow outdoors: Apr 12 to May 3Plant for fall: Aug 17 to Aug 31
Sow outdoors: Apr 12 to Apr 26
Transplant outside: Apr 19 to May 10
Plant for fall: Oct 19 to Nov 23
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Altus, OK
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 11 – Jan 25 | Mar 8 – Mar 22 | — | — |
| Peppers | Jan 25 – Feb 8 | Apr 19 – May 3 | — | — |
| Eggplant | Jan 25 – Feb 8 | Apr 19 – May 3 | — | — |
| Tomatoes | Feb 8 – Feb 22 | Apr 12 – Apr 26 | — | — |
| Lettuce | Feb 8 – Feb 22 | Mar 15 – Mar 29 | Mar 8 – Apr 12 | Sep 7 – Oct 5 |
| Kale | Feb 8 – Feb 22 | Mar 8 – Mar 22 | Mar 8 – Mar 22 | Aug 24 – Sep 14 |
| Broccoli | Feb 8 – Feb 22 | Mar 22 – Apr 5 | — | Jul 27 – Aug 17 |
| Cabbage | Feb 8 – Feb 22 | Mar 15 – Mar 29 | — | Jul 27 – Aug 17 |
| Cauliflower | Feb 8 – Feb 22 | Mar 22 – Apr 5 | — | Jul 27 – Aug 17 |
| Okra | Feb 22 – Mar 8 | Apr 26 – May 10 | Apr 26 – May 10 | — |
| Basil | Feb 22 – Mar 8 | Apr 12 – Apr 26 | — | — |
| Peas | — | — | Feb 22 – Mar 15 | Aug 10 – Aug 31 |
| Spinach | — | — | Feb 22 – Mar 15 | Sep 7 – Sep 28 |
| Radishes | — | — | Mar 1 – Apr 12 | Sep 21 – Oct 12 |
| Cucumbers | Mar 8 – Mar 15 | Apr 19 – Apr 26 | Apr 12 – Apr 26 | Aug 17 – Aug 31 |
| Zucchini & Summer Squash | Mar 8 – Mar 15 | — | Apr 12 – Apr 26 | Aug 24 – Sep 7 |
| Winter Squash & Pumpkins | Mar 8 – Mar 15 | — | Apr 12 – Apr 26 | — |
| Melons & Watermelon | Mar 8 – Mar 15 | Apr 19 – May 3 | — | — |
| Carrots | — | — | Mar 15 – Apr 12 | Aug 10 – Aug 24 |
| Beets | — | — | Mar 15 – Apr 12 | Aug 24 – Sep 7 |
| Potatoes | — | — | Mar 15 – Apr 5 | — |
| Swiss Chard | — | — | Mar 22 – Apr 19 | Aug 24 – Sep 7 |
| Cilantro | — | — | Mar 22 – Apr 12 | Sep 7 – Sep 28 |
| Green Beans | — | — | Apr 12 – May 3 | Aug 17 – Aug 31 |
| Sweet Corn | — | — | Apr 12 – Apr 26 | — |
| Sweet Potatoes | — | Apr 19 – May 10 | — | — |
| Garlic | — | — | — | Oct 19 – Nov 23 |
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 Altus Irig Rsch Stn, OK weather station, 7 km away (elevation 1,381 ft (421 m)).
ZIP codes in Altus: 73521 73522
Frost dates near Altus
- Martha Apr 10 · Oct 29
- Altus Afb Apr 3 · Nov 4
- Blair Apr 10 · Oct 29
- Olustee Apr 3 · Nov 4
- Elmer Apr 3 · Nov 4
- Headrick Apr 5 · Nov 2
- Duke Apr 3 · Nov 4
- Tipton Apr 3 · Nov 6
Frequently asked questions
When is the last frost in Altus, OK?
The median last spring frost in Altus, OK is April 5. There is still about a 10% chance of frost after April 21, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Altus, OK?
The median first fall frost is November 2, with about a 10% chance of frost before October 19.
How long is the growing season in Altus, OK?
About 211 days between the median last spring frost and first fall frost.
What planting zone is Altus, OK?
Altus, OK is in USDA hardiness zone 7b.