Port Gibson, Mississippi climate: Normal weather by month, frost dates and records
Port Gibson's normal year runs from 36°F January nights to 93°F July afternoons, with 56.3 inches of precipitation and less than an inch of snow (0.5 in) a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 18.8°C, January lows of 2°C, July highs of 34°C, 1,429 mm of precipitation a year.
- NOAA stationPort Gibson (1 mi NE)
- Station IDUSC00227132
- Location31.98°N 90.97°W
- Elevation120 ft (37 m)
- Population1,166
On October 23, the normal high in Port Gibson is 78°F and the normal low 50°F, and the chance of measurable rain or snow is 20%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Port Gibson.
- Jan 60° 36°
- Feb 64° 38°
- Mar 71° 46°
- Apr 78° 53°
- May 85° 62°
- Jun 91° 69°
- Jul 93° 72°
- Aug 93° 71°
- Sep 89° 65°
- Oct 80° 53°
- Nov 69° 43°
- Dec 62° 38°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Port Gibson each month?
July is the warmest month, with normal highs of 93°F; January the coldest, with normal lows of 36°F. The most precipitation falls in January (6.10 in), the least in August (3.56 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 60°F | 36°F | 47.6°F | 6.10 | 10 | <1 | 15 | 10 h 20 min |
| February | 64°F | 38°F | 50.9°F | 5.06 | 8 | <1 | 10 | 11 h |
| March | 71°F | 46°F | 58.4°F | 6.01 | 9 | <1 | 4 | 12 h |
| April | 78°F | 53°F | 65.2°F | 5.45 | 8 | <1 | <1 | 13 h |
| May | 85°F | 62°F | 73.2°F | 4.47 | 8 | 4 | <1 | 13 h 50 min |
| June | 91°F | 69°F | 79.8°F | 4.05 | 9 | 16 | <1 | 14 h 10 min |
| July | 93°F | 72°F | 82.3°F | 3.94 | 9 | 22 | <1 | 14 h |
| August | 93°F | 71°F | 82.2°F | 3.56 | 8 | 23 | <1 | 13 h 20 min |
| September | 89°F | 65°F | 77.2°F | 3.75 | 7 | 13 | <1 | 12 h 20 min |
| October | 80°F | 53°F | 66.6°F | 4.11 | 6 | 1 | 1 | 11 h 30 min |
| November | 69°F | 43°F | 55.9°F | 4.44 | 7 | <1 | 6 | 10 h 30 min |
| December | 62°F | 38°F | 49.8°F | 5.32 | 9 | <1 | 13 | 10 h |
| Year (annual) | 78°F | 54°F | 65.8°F | 56.26 | 98 | 80 | 49 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 15°C | 2°C | 8.7°C | 155 mm |
| February | 18°C | 3°C | 10.5°C | 129 mm |
| March | 22°C | 8°C | 14.7°C | 153 mm |
| April | 26°C | 11°C | 18.4°C | 138 mm |
| May | 29°C | 16°C | 22.9°C | 114 mm |
| June | 33°C | 21°C | 26.6°C | 103 mm |
| July | 34°C | 22°C | 27.9°C | 100 mm |
| August | 34°C | 22°C | 27.9°C | 90 mm |
| September | 32°C | 19°C | 25.1°C | 95 mm |
| October | 27°C | 12°C | 19.2°C | 104 mm |
| November | 21°C | 6°C | 13.3°C | 113 mm |
| December | 16°C | 3°C | 9.9°C | 135 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00227132; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Port Gibson?
Normal highs sit between 65°F and 85°F in March, April, May, October and November. Of those, October has the fewest days with rain (6).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00227132.
When is the last frost in Port Gibson?
In Port Gibson, the last spring frost (32°F) comes after March 17 in half of years and after April 7 in one year in ten; the first autumn frost comes before November 12 in half of years and before October 29 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- March 171 year in 10 after April 7; 9 in 10 after February 24
- First autumn frost, half of years before
- November 121 year in 10 before October 29; 9 in 10 before December 1
NOAA puts the median frost-free season at 241 days, and the season without a hard freeze (28°F) at 271 days.
A hard freeze (28°F) comes after March 1 in half of springs and before November 25 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Port Gibson in zone 8b in ZIP code 39150, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Port Gibson's NOAA station is in zone 8b: the coldest night of a typical year reaches 18°F (20 complete years).
Frost dates for every NOAA station in Mississippi · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00227132; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Port Gibson?
In a normal year in Port Gibson, 80 days a year reach 90°F (2 of them 100°F or more), 49 nights fall to 32°F or colder and 98 days bring measurable precipitation.
- Days at 90°F or more
- 80a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 49a normal year
- Days that stay below freezing
- 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 98a normal year
The highest temperature in this station's record (since 1893) is 107°F, on August 18, 1909; the lowest is −5°F, on January 27, 1940.
The wettest calendar year on that record is 2025, with 85.06 in; the snowiest season is 1967–68, with 10.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00227132; records: ACIS (NOAA Regional Climate Centers), station USC00227132. Records use complete months only; a month missing more than three days is left out.
How sunny is Port Gibson?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Port Gibson, 4.6 kWh per square metre a day. September is the sunniest month (82%) and February the cloudiest (68%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 70% | 2.8 |
| February | 68% | 3.4 |
| March | 73% | 4.5 |
| April | 78% | 5.6 |
| May | 80% | 6.1 |
| June | 80% | 6.3 |
| July | 79% | 6.0 |
| August | 81% | 5.7 |
| September | 82% | 5.1 |
| October | 81% | 4.3 |
| November | 78% | 3.3 |
| December | 69% | 2.5 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Port Gibson need?
A normal year in Port Gibson brings 2,163 heating degree days, 60% fewer than the median U.S. place (5,373), and 2,470 cooling degree days, 2.7 times the median (908). Three months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 6,266 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 546 | 6 |
| February | 404 | 9 |
| March | 241 | 38 |
| April | 95 | 102 |
| May | 13 | 267 |
| June | 0 | 444 |
| July | 0 | 538 |
| August | 0 | 532 |
| September | 3 | 369 |
| October | 84 | 134 |
| November | 296 | 24 |
| December | 480 | 9 |
| Year (annual) | 2,163 | 2,470 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00227132. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Port Gibson been warmer than normal lately?
2025 averaged 67.8°F, 2.0°F above the 1991-2020 normal of 65.8°F. 3 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 65.5°F | −0.3°F | 53.31 |
| 2022 | 65.8°F | at normal | 58.84 |
| 2023 | 68.0°F | +2.2°F | 40.86 |
| 2024 | 67.6°F | +1.8°F | 79.88 |
| 2025 | 67.8°F | +2.0°F | 85.06 |
Over 87 complete years from 1892 to 2022, the station's annual mean temperature rose at a fitted 0.4°F per century (+0.02°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00227132; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Port Gibson's climate compare?
Port Gibson is warmer than 59 of the other 80 places with their own NOAA record in Mississippi, and wetter than 9. Across the 7,247 U.S. stations with normals, its annual mean of 65.8°F is warmer than 90%.
In the Köppen classification computed from these normals, Port Gibson is Cfa: temperate, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Port Gibson share this climate record?
3 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Newellton, LA828 people · 17 mi W
- Hermanville, MS527 people · 8 mi E
- Pattison, MS57 people · 8 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Port Gibson's climate
What is the coldest month in Port Gibson?
January, with a normal high of 60°F and a normal low of 36°F. The warmest is July (93°F by day, 72°F at night).
Does it snow in Port Gibson?
Rarely: NOAA's normal is 0.5 inch a year.
What is the rainiest month in Port Gibson?
January, with 6.10 in of precipitation in a normal year; the driest is August with 3.56 in.
What plant hardiness zone is Port Gibson in?
The USDA's 2023 map puts Port Gibson in zone 8b in ZIP code 39150, the nearest ZIP area. By the same method at Port Gibson's NOAA station, the coldest night of a typical year reaches 18°F (20 years, 1991-2020): zone 8b.
How late can frost come in Port Gibson?
In half of years the last 32°F night comes after March 17; in one year in ten it comes after April 7. Waiting until April 7 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Mississippi climateThe statewide normals and every place in the state
- St. Joseph, LA16 miles from this station, 65.5°F a year
- Tallulah, LA25 miles from this station, 66.1°F a year
- Vicksburg, MS28 miles from this station, 66.3°F a year
- Oakley Experiment Station, MS31 miles from this station, 65.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made