Last spring frost
Mar 27
Frost Dates for Decatur, AL
First fall frost
Nov 3
Growing season
221 days
Hardiness zone
8a
In an average year around Decatur, AL, the last spring frost (32°F) is about Mar 27 and the first fall frost is about Nov 3, giving roughly a 221-day growing season. To be safe most years, wait until Mar 8 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 20 | Apr 5 | Mar 22 |
| Freeze (32°F) | Apr 10 | Mar 27 | Mar 8 |
| Hard (28°F) | Apr 1 | Mar 14 | Feb 23 |
| Severe (24°F) | Mar 21 | Feb 28 | Feb 3 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 20 | Apr 15 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 28 | Mar 22 |
| 32°F | Apr 10 | Apr 5 | Apr 2 | Mar 30 | Mar 27 | Mar 24 | Mar 19 | Mar 15 | Mar 8 |
| 28°F | Apr 1 | Mar 27 | Mar 22 | Mar 17 | Mar 14 | Mar 9 | Mar 5 | Feb 28 | Feb 23 |
| 24°F | Mar 21 | Mar 14 | Mar 8 | Mar 4 | Feb 28 | Feb 24 | Feb 19 | Feb 13 | Feb 3 |
| 20°F | Mar 9 | Mar 2 | Feb 25 | Feb 19 | Feb 12 | Feb 6 | Jan 31 | Jan 26 | Jan 13 |
| 16°F | Feb 27 | Feb 16 | Feb 7 | Feb 2 | Jan 30 | Jan 25 | Jan 18 | Jan 10 | Jan 3 |
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 13 | Oct 25 | Nov 6 |
| Freeze (32°F) | Oct 22 | Nov 3 | Nov 20 |
| Hard (28°F) | Nov 1 | Nov 15 | Dec 4 |
| Severe (24°F) | Nov 8 | Nov 29 | Dec 26 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 13 | Oct 18 | Oct 21 | Oct 23 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 6 |
| 32°F | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 13 | Nov 20 |
| 28°F | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 15 | Nov 18 | Nov 22 | Nov 28 | Dec 4 |
| 24°F | Nov 8 | Nov 15 | Nov 19 | Nov 24 | Nov 29 | Dec 2 | Dec 6 | Dec 12 | Dec 26 |
| 20°F | Nov 21 | Nov 29 | Dec 3 | Dec 8 | Dec 13 | Dec 22 | Dec 30 | Jan 4 | Jan 14 |
| 16°F | Dec 7 | Dec 17 | Dec 26 | Jan 1 | Jan 4 | Jan 9 | Jan 14 | 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: Decatur Pryor Fld, Al, about 1.2 miles away@if(!empty($station['elevation_ft'])), at 592 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 Decatur, AL?
On average, the last spring frost (32°F) around Decatur, AL is about Mar 27. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 8.
When is the first frost in the fall?
The first fall frost around Decatur, AL typically arrives about Nov 3. 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 27 on average, or Mar 8 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 221 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 35671 Planting calendar → Alabama frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026