Last spring frost
Apr 11
Frost Dates for Sweetwater, OK
First fall frost
Oct 26
Growing season
197 days
Hardiness zone
7b
In an average year around Sweetwater, OK, the last spring frost (32°F) is about Apr 11 and the first fall frost is about Oct 26, giving roughly a 197-day growing season. To be safe most years, wait until Mar 27 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | May 5 | Apr 22 | Apr 6 |
| Freeze (32°F) | Apr 29 | Apr 11 | Mar 27 |
| Hard (28°F) | Apr 18 | Apr 1 | Mar 10 |
| Severe (24°F) | Apr 5 | Mar 17 | Feb 28 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 5 | May 1 | Apr 29 | Apr 26 | Apr 22 | Apr 18 | Apr 15 | Apr 11 | Apr 6 |
| 32°F | Apr 29 | Apr 23 | Apr 19 | Apr 15 | Apr 11 | Apr 8 | Apr 4 | Apr 1 | Mar 27 |
| 28°F | Apr 18 | Apr 11 | Apr 6 | Apr 4 | Apr 1 | Mar 28 | Mar 24 | Mar 18 | Mar 10 |
| 24°F | Apr 5 | Mar 31 | Mar 26 | Mar 22 | Mar 17 | Mar 12 | Mar 8 | Mar 4 | Feb 28 |
| 20°F | Mar 25 | Mar 17 | Mar 12 | Mar 8 | Mar 5 | Mar 3 | Feb 28 | Feb 24 | Feb 15 |
| 16°F | Mar 13 | Mar 7 | Mar 3 | Mar 1 | Feb 25 | Feb 21 | Feb 15 | Feb 7 | Jan 30 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Oct 4 | Oct 18 | Oct 29 |
| Freeze (32°F) | Oct 14 | Oct 26 | Nov 9 |
| Hard (28°F) | Oct 20 | Nov 5 | Nov 20 |
| Severe (24°F) | Oct 28 | Nov 14 | Dec 1 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 4 | Oct 10 | Oct 13 | Oct 16 | Oct 18 | Oct 20 | Oct 23 | Oct 25 | Oct 29 |
| 32°F | Oct 14 | Oct 18 | Oct 21 | Oct 24 | Oct 26 | Oct 29 | Nov 1 | Nov 5 | Nov 9 |
| 28°F | Oct 20 | Oct 26 | Oct 30 | Nov 2 | Nov 5 | Nov 7 | Nov 11 | Nov 15 | Nov 20 |
| 24°F | Oct 28 | Nov 3 | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 21 | Nov 26 | Dec 1 |
| 20°F | Nov 7 | Nov 13 | Nov 18 | Nov 21 | Nov 25 | Nov 29 | Dec 2 | Dec 6 | Dec 12 |
| 16°F | Nov 17 | Nov 24 | Nov 29 | Dec 2 | Dec 6 | Dec 11 | Dec 16 | Dec 23 | Jan 1 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Erick, Ok, about 14.1 miles away@if(!empty($station['elevation_ft'])), at 2,060 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Sweetwater, OK?
On average, the last spring frost (32°F) around Sweetwater, OK is about Apr 11. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 27.
When is the first frost in the fall?
The first fall frost around Sweetwater, OK typically arrives about Oct 26. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 11 on average, or Mar 27 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 197 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 73666 Planting calendar → Oklahoma frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026