Last spring frost
Mar 1
Frost Dates for Simpson, LA
First fall frost
Nov 23
Growing season
268 days
Hardiness zone
9a
In an average year around Simpson, LA, the last spring frost (32°F) is about Mar 1 and the first fall frost is about Nov 23, giving roughly a 268-day growing season. To be safe most years, wait until Jan 31 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 5 | Mar 15 | Feb 23 |
| Freeze (32°F) | Mar 24 | Mar 1 | Jan 31 |
| Hard (28°F) | Mar 9 | Feb 7 | Jan 2 |
| Severe (24°F) | Feb 28 | Jan 23 | Dec 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 5 | Mar 31 | Mar 25 | Mar 19 | Mar 15 | Mar 11 | Mar 6 | Mar 1 | Feb 23 |
| 32°F | Mar 24 | Mar 16 | Mar 10 | Mar 5 | Mar 1 | Feb 26 | Feb 20 | Feb 12 | Jan 31 |
| 28°F | Mar 9 | Mar 2 | Feb 25 | Feb 16 | Feb 7 | Jan 31 | Jan 26 | Jan 16 | Jan 2 |
| 24°F | Feb 28 | Feb 15 | Feb 5 | Jan 30 | Jan 23 | Jan 17 | Jan 11 | Jan 2 | Dec 22 |
| 20°F | Feb 9 | Feb 1 | Jan 29 | Jan 22 | Jan 16 | Jan 9 | Jan 5 | Dec 31 | Dec 21 |
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 28 | Nov 11 | Dec 1 |
| Freeze (32°F) | Nov 4 | Nov 23 | Dec 20 |
| Hard (28°F) | Nov 15 | Dec 10 | Jan 14 |
| Severe (24°F) | Nov 30 | Jan 1 | Feb 2 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 28 | Nov 1 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 18 | Nov 23 | Dec 1 |
| 32°F | Nov 4 | Nov 10 | Nov 15 | Nov 19 | Nov 23 | Nov 27 | Dec 1 | Dec 7 | Dec 20 |
| 28°F | Nov 15 | Nov 24 | Nov 29 | Dec 4 | Dec 10 | Dec 18 | Dec 28 | Jan 5 | Jan 14 |
| 24°F | Nov 30 | Dec 9 | Dec 19 | Dec 27 | Jan 1 | Jan 5 | Jan 12 | Jan 19 | Feb 2 |
| 20°F | Dec 15 | Dec 26 | Jan 1 | Jan 3 | Jan 7 | Jan 12 | Jan 19 | Jan 30 | Feb 4 |
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: Ft Polk Fullerton Lndg Strip, La, about 9.2 miles away@if(!empty($station['elevation_ft'])), at 310 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 Simpson, LA?
On average, the last spring frost (32°F) around Simpson, LA is about Mar 1. In cooler years it can run later, so for a safer bet many gardeners wait until Jan 31.
When is the first frost in the fall?
The first fall frost around Simpson, LA typically arrives about Nov 23. 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 1 on average, or Jan 31 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 268 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 71474 Planting calendar → Louisiana frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026