Last spring frost
Mar 28
Frost Dates for Foster, OK
First fall frost
Nov 7
Growing season
227 days
Hardiness zone
7b
In an average year around Foster, OK, the last spring frost (32°F) is about Mar 28 and the first fall frost is about Nov 7, giving roughly a 227-day growing season. To be safe most years, wait until Mar 6 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) | Apr 26 | Apr 9 | Mar 22 |
| Freeze (32°F) | Apr 18 | Mar 28 | Mar 6 |
| Hard (28°F) | Apr 3 | Mar 12 | Feb 23 |
| Severe (24°F) | Mar 19 | Mar 2 | Feb 7 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 26 | Apr 21 | Apr 18 | Apr 14 | Apr 9 | Apr 6 | Apr 3 | Mar 29 | Mar 22 |
| 32°F | Apr 18 | Apr 9 | Apr 5 | Apr 1 | Mar 28 | Mar 22 | Mar 17 | Mar 13 | Mar 6 |
| 28°F | Apr 3 | Mar 28 | Mar 22 | Mar 17 | Mar 12 | Mar 8 | Mar 4 | Feb 28 | Feb 23 |
| 24°F | Mar 19 | Mar 13 | Mar 9 | Mar 5 | Mar 2 | Feb 26 | Feb 21 | Feb 15 | Feb 7 |
| 20°F | Mar 8 | Mar 3 | Feb 26 | Feb 22 | Feb 14 | Feb 9 | Feb 1 | Jan 28 | Jan 18 |
| 16°F | Feb 28 | Feb 18 | Feb 9 | Feb 3 | Jan 29 | Jan 24 | Jan 18 | Jan 7 | Dec 27 |
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 16 | Oct 29 | Nov 12 |
| Freeze (32°F) | Oct 23 | Nov 7 | Nov 21 |
| Hard (28°F) | Oct 30 | Nov 16 | Dec 2 |
| Severe (24°F) | Nov 7 | Nov 27 | Dec 17 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 16 | Oct 21 | Oct 24 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 12 |
| 32°F | Oct 23 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 9 | Nov 13 | Nov 16 | Nov 21 |
| 28°F | Oct 30 | Nov 5 | Nov 9 | Nov 13 | Nov 16 | Nov 20 | Nov 24 | Nov 27 | Dec 2 |
| 24°F | Nov 7 | Nov 14 | Nov 20 | Nov 24 | Nov 27 | Dec 1 | Dec 4 | Dec 8 | Dec 17 |
| 20°F | Nov 17 | Nov 25 | Nov 30 | Dec 4 | Dec 9 | Dec 13 | Dec 20 | Dec 26 | Jan 5 |
| 16°F | Nov 28 | Dec 5 | Dec 11 | Dec 17 | Dec 24 | Dec 31 | Jan 6 | Jan 14 | Jan 30 |
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: Velma 7Nw Mesonet, Ok, about 12.2 miles away@if(!empty($station['elevation_ft'])), at 1,118 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 Foster, OK?
On average, the last spring frost (32°F) around Foster, OK is about Mar 28. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 6.
When is the first frost in the fall?
The first fall frost around Foster, OK typically arrives about Nov 7. 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 Mar 28 on average, or Mar 6 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 227 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 73434 Planting calendar → Oklahoma frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026