Last spring frost
Mar 17
Frost Dates for Port Gibson, MS
First fall frost
Nov 12
Growing season
241 days
Hardiness zone
8b
In an average year around Port Gibson, MS, the last spring frost (32°F) is about Mar 17 and the first fall frost is about Nov 12, giving roughly a 241-day growing season. To be safe most years, wait until Feb 24 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 19 | Mar 31 | Mar 12 |
| Freeze (32°F) | Apr 7 | Mar 17 | Feb 24 |
| Hard (28°F) | Mar 22 | Mar 1 | Feb 3 |
| Severe (24°F) | Mar 11 | Feb 15 | Jan 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 19 | Apr 12 | Apr 7 | Apr 4 | Mar 31 | Mar 28 | Mar 25 | Mar 19 | Mar 12 |
| 32°F | Apr 7 | Apr 1 | Mar 27 | Mar 21 | Mar 17 | Mar 12 | Mar 7 | Mar 2 | Feb 24 |
| 28°F | Mar 22 | Mar 14 | Mar 9 | Mar 5 | Mar 1 | Feb 26 | Feb 21 | Feb 15 | Feb 3 |
| 24°F | Mar 11 | Mar 4 | Feb 27 | Feb 22 | Feb 15 | Feb 10 | Feb 3 | Jan 29 | Jan 15 |
| 20°F | Mar 1 | Feb 20 | Feb 10 | Feb 4 | Jan 31 | Jan 27 | Jan 18 | Jan 9 | Dec 30 |
| 16°F | Feb 18 | Feb 7 | Feb 2 | Jan 30 | Jan 23 | Jan 18 | Jan 12 | 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 20 | Nov 2 | Nov 17 |
| Freeze (32°F) | Oct 29 | Nov 12 | Dec 1 |
| Hard (28°F) | Nov 5 | Nov 25 | Dec 27 |
| Severe (24°F) | Nov 15 | Dec 13 | Jan 18 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 20 | Oct 24 | Oct 28 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 11 | Nov 17 |
| 32°F | Oct 29 | Nov 2 | Nov 5 | Nov 8 | Nov 12 | Nov 15 | Nov 20 | Nov 24 | Dec 1 |
| 28°F | Nov 5 | Nov 11 | Nov 16 | Nov 21 | Nov 25 | Nov 30 | Dec 5 | Dec 10 | Dec 27 |
| 24°F | Nov 15 | Nov 24 | Dec 1 | Dec 6 | Dec 13 | Dec 25 | Jan 1 | Jan 6 | Jan 18 |
| 20°F | Dec 4 | Dec 12 | Dec 25 | Jan 1 | Jan 4 | Jan 9 | Jan 15 | Jan 25 | Feb 5 |
| 16°F | Dec 20 | Dec 31 | Jan 4 | Jan 7 | Jan 11 | Jan 16 | Jan 26 | Feb 1 | Feb 14 |
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: Port Gibson 1 Ne, Ms, about 0.8 miles away@if(!empty($station['elevation_ft'])), at 120 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 Port Gibson, MS?
On average, the last spring frost (32°F) around Port Gibson, MS is about Mar 17. In cooler years it can run later, so for a safer bet many gardeners wait until Feb 24.
When is the first frost in the fall?
The first fall frost around Port Gibson, MS typically arrives about Nov 12. 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 17 on average, or Feb 24 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 241 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 39150 Planting calendar → Mississippi frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026