Last spring frost
Mar 26
Frost Dates for Thornton, AR
First fall frost
Nov 6
Growing season
226 days
Hardiness zone
8a
In an average year around Thornton, AR, the last spring frost (32°F) is about Mar 26 and the first fall frost is about Nov 6, giving roughly a 226-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 24 | Apr 7 | Mar 21 |
| Freeze (32°F) | Apr 13 | Mar 26 | Mar 6 |
| Hard (28°F) | Mar 30 | Mar 10 | Feb 21 |
| Severe (24°F) | Mar 15 | Feb 26 | Jan 31 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 24 | Apr 19 | Apr 14 | Apr 11 | Apr 7 | Apr 4 | Apr 1 | Mar 28 | Mar 21 |
| 32°F | Apr 13 | Apr 7 | Apr 3 | Mar 30 | Mar 26 | Mar 22 | Mar 18 | Mar 14 | Mar 6 |
| 28°F | Mar 30 | Mar 24 | Mar 19 | Mar 15 | Mar 10 | Mar 6 | Mar 2 | Feb 27 | Feb 21 |
| 24°F | Mar 15 | Mar 9 | Mar 5 | Mar 1 | Feb 26 | Feb 21 | Feb 15 | Feb 8 | Jan 31 |
| 20°F | Mar 6 | Feb 28 | Feb 20 | Feb 13 | Feb 7 | Feb 1 | Jan 28 | Jan 21 | Jan 11 |
| 16°F | Feb 22 | Feb 11 | Feb 4 | Jan 31 | Jan 26 | Jan 19 | Jan 13 | Jan 6 | Dec 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 15 | Oct 29 | Nov 12 |
| Freeze (32°F) | Oct 24 | Nov 6 | Nov 24 |
| Hard (28°F) | Nov 1 | Nov 19 | Dec 8 |
| Severe (24°F) | Nov 11 | Dec 3 | Dec 29 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 15 | Oct 20 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 12 |
| 32°F | Oct 24 | Oct 29 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 13 | Nov 18 | Nov 24 |
| 28°F | Nov 1 | Nov 7 | Nov 11 | Nov 15 | Nov 19 | Nov 24 | Nov 28 | Dec 3 | Dec 8 |
| 24°F | Nov 11 | Nov 18 | Nov 25 | Nov 30 | Dec 3 | Dec 7 | Dec 13 | Dec 21 | Dec 29 |
| 20°F | Nov 25 | Dec 1 | Dec 8 | Dec 16 | Dec 23 | Dec 28 | Jan 1 | Jan 6 | Jan 16 |
| 16°F | Dec 11 | Dec 22 | Dec 29 | Jan 1 | Jan 5 | Jan 9 | Jan 15 | Jan 21 | Feb 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: Fordyce, Ar, about 8.3 miles away@if(!empty($station['elevation_ft'])), at 230 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 Thornton, AR?
On average, the last spring frost (32°F) around Thornton, AR is about Mar 26. 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 Thornton, AR typically arrives about Nov 6. 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 26 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 226 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 71766 Planting calendar → Arkansas frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026