Frost dates / Alabama / Decatur
Frost dates in Decatur, AL
The station on this page is DECATUR 4SE, AL US (USC00012209), 3.2 miles from the city point. Population in the Census 2024 estimate is 57,974.
Zone 8aUSDA average annual extreme minimum 10°F to 15°F, from ZIP 35601 (2.5 miles from the city point used on this page).
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
Last 32°F in spring
NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.
| Probability | Date | How to read it |
|---|---|---|
| 90% | March 5 | Earlier date. A last 32°F on or after this day is common. |
| 50% | March 26 | Median. |
| 10% | April 9 | Later date. A last 32°F on or after this day is uncommon. |
First 32°F in fall
NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.
| Probability | Date | How to read it |
|---|---|---|
| 10% | October 26 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | November 7 | Median. |
| 90% | November 26 | Later date. A first 32°F on or before this day is common. |
32°F growing-season length
Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.
| Probability the season is at least this long | Days |
|---|---|
| 10% | 252 |
| 50% | 228 |
| 90% | 205 |
28°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | March 30 | March 12 | February 21 |
| First, on or before | November 4 | November 19 | December 10 |
| Season at least | 279 days | 253 days | 228 days |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | April 22 | April 5 | March 21 |
| First, on or before | October 16 | October 29 | November 11 |
| Season at least | 227 days | 205 days | 187 days |
Station DECATUR 4SE, AL US (USC00012209). Completeness flag R, 19 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 167.6 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.
Check a crop against this station
Decatur, AL
Zone 8aAverage annual extreme minimum 10°F to 15°F
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
Alabama. Nearest qualified station: DECATUR 4SE, AL US (USC00012209), 3.2 miles. Median last 32°F March 26. Median first 32°F November 7. The 50% growing-season length is 228 days.
32°F probabilities at this station
| 10% | 50% | 90% | |
|---|---|---|---|
| Last 32°F on or after | April 9 | March 26 | March 5 |
| First 32°F on or before | October 26 | November 7 | November 26 |
Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.

Planting calendar
Frost dates for Alabama are above. Planting windows appear for states with a cited extension guide. The fall and seed tools use the numbers you enter and the station dates.
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