St. Joseph, Louisiana climate: Normal weather by month, frost dates and records
St. Joseph's normal year runs from 36°F January nights to 93°F July afternoons, with 58.2 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 18.6°C, January lows of 2°C, July highs of 34°C, 1,479 mm of precipitation a year.
- NOAA stationSt Joseph (3 mi N)
- Station IDUSC00168163
- Location31.95°N 91.23°W
- Elevation78 ft (24 m)
- Population778
On October 22, the normal high in St. Joseph 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 St. Joseph.
- Jan 59° 36°
- Feb 63° 39°
- Mar 70° 46°
- Apr 78° 53°
- May 85° 62°
- Jun 91° 69°
- Jul 93° 71°
- Aug 93° 70°
- Sep 90° 64°
- Oct 81° 53°
- Nov 70° 43°
- Dec 61° 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 St. Joseph 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 (6.25 in), the least in September (3.56 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 59°F | 36°F | 47.0°F | 6.25 | 10 | <1 | 11 | 10 h 20 min |
| February | 63°F | 39°F | 50.9°F | 5.50 | 9 | <1 | 7 | 11 h |
| March | 70°F | 46°F | 58.0°F | 5.71 | 9 | <1 | 2 | 12 h |
| April | 78°F | 53°F | 65.1°F | 4.86 | 7 | 1 | <1 | 13 h |
| May | 85°F | 62°F | 73.4°F | 4.37 | 7 | 9 | <1 | 13 h 50 min |
| June | 91°F | 69°F | 79.6°F | 4.17 | 9 | 21 | <1 | 14 h 10 min |
| July | 93°F | 71°F | 81.9°F | 4.68 | 9 | 27 | <1 | 14 h |
| August | 93°F | 70°F | 81.5°F | 4.39 | 8 | 27 | <1 | 13 h 20 min |
| September | 90°F | 64°F | 76.8°F | 3.56 | 6 | 19 | <1 | 12 h 20 min |
| October | 81°F | 53°F | 66.6°F | 3.80 | 6 | 4 | <1 | 11 h 30 min |
| November | 70°F | 43°F | 56.3°F | 5.39 | 7 | <1 | 4 | 10 h 30 min |
| December | 61°F | 38°F | 49.4°F | 5.55 | 9 | <1 | 9 | 10 h |
| Year (annual) | 78°F | 54°F | 65.5°F | 58.23 | 94 | 108 | 33 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 15°C | 2°C | 8.3°C | 159 mm |
| February | 17°C | 4°C | 10.5°C | 140 mm |
| March | 21°C | 8°C | 14.4°C | 145 mm |
| April | 25°C | 12°C | 18.4°C | 123 mm |
| May | 29°C | 17°C | 23.0°C | 111 mm |
| June | 33°C | 20°C | 26.4°C | 106 mm |
| July | 34°C | 22°C | 27.7°C | 119 mm |
| August | 34°C | 21°C | 27.5°C | 112 mm |
| September | 32°C | 18°C | 24.9°C | 90 mm |
| October | 27°C | 11°C | 19.2°C | 97 mm |
| November | 21°C | 6°C | 13.5°C | 137 mm |
| December | 16°C | 3°C | 9.7°C | 141 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00168163; 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 St. Joseph?
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 USC00168163.
When is the last frost in St. Joseph?
In St. Joseph, the last spring frost (32°F) comes after March 13 in half of years and after April 4 in one year in ten; the first autumn frost comes before November 10 in half of years and before October 27 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 131 year in 10 after April 4; 9 in 10 after February 20
- First autumn frost, half of years before
- November 101 year in 10 before October 27; 9 in 10 before December 1
NOAA puts the median frost-free season at 242 days, and the season without a hard freeze (28°F) at 271 days.
A hard freeze (28°F) comes after February 27 in half of springs and before November 22 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts St. Joseph in zone 8b in ZIP code 71366, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, St. Joseph's NOAA station is in zone 9a: the coldest night of a typical year reaches 20°F (16 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Louisiana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00168163; 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 St. Joseph?
In a normal year in St. Joseph, 108 days a year reach 90°F (4 of them 100°F or more), 33 nights fall to 32°F or colder and 94 days bring measurable precipitation.
- Days at 90°F or more
- 108a normal year
- Days at 100°F or more
- 4a normal year
- Nights at 32°F or colder
- 33a normal year
- Days that stay below freezing
- 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 94a normal year
The highest temperature in this station's record (since 1894) is 107°F, on September 1, 2000; the lowest is −8°F, on January 27, 1940.
The wettest calendar year on that record is 1940, with 83.44 in; the snowiest season is 1935–36, with 12.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00168163; records: ACIS (NOAA Regional Climate Centers), station USC00168163. Records use complete months only; a month missing more than three days is left out.
How sunny is St. Joseph?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around St. Joseph, 4.7 kWh per square metre a day. August is the sunniest month (83%) and February the cloudiest (67%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 70% | 2.8 |
| February | 67% | 3.3 |
| March | 72% | 4.4 |
| April | 78% | 5.6 |
| May | 80% | 6.2 |
| June | 82% | 6.4 |
| July | 82% | 6.2 |
| August | 83% | 5.8 |
| September | 83% | 5.2 |
| October | 82% | 4.3 |
| November | 79% | 3.3 |
| December | 70% | 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 St. Joseph need?
A normal year in St. Joseph brings 2,171 heating degree days, 60% fewer than the median U.S. place (5,373), and 2,398 cooling degree days, 2.6 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 6,196 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 559 | 2 |
| February | 403 | 7 |
| March | 243 | 27 |
| April | 90 | 93 |
| May | 11 | 272 |
| June | 0 | 437 |
| July | 0 | 525 |
| August | 0 | 511 |
| September | 5 | 359 |
| October | 85 | 133 |
| November | 284 | 24 |
| December | 492 | 8 |
| Year (annual) | 2,171 | 2,398 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00168163. 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 St. Joseph been warmer than normal lately?
2022 averaged 67.0°F, 1.5°F above the 1991-2020 normal of 65.5°F.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2022 | 67.0°F | +1.5°F | 52.81 |
Over 75 complete years from 1909 to 2022, the station's annual mean temperature rose at a fitted 0.8°F per century (+0.05°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00168163; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does St. Joseph's climate compare?
St. Joseph is warmer than 16 of the other 64 places with their own NOAA record in Louisiana, and wetter than 18. Across the 7,247 U.S. stations with normals, its annual mean of 65.5°F is warmer than 89%.
In the Köppen classification computed from these normals, St. Joseph 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 St. Joseph share this climate record?
2 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.
- Fayette, MS1,342 people · 19 mi SE
- Alcorn State University, MS1,007 people · 7 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 St. Joseph's climate
What is the coldest month in St. Joseph?
January, with a normal high of 59°F and a normal low of 36°F. The warmest is July (93°F by day, 71°F at night).
Does it snow in St. Joseph?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in St. Joseph?
January, with 6.25 in of precipitation in a normal year; the driest is September with 3.56 in.
What plant hardiness zone is St. Joseph in?
The USDA's 2023 map puts St. Joseph in zone 8b in ZIP code 71366, the nearest ZIP area. By the same method at St. Joseph's NOAA station, the coldest night of a typical year reaches 20°F (16 years, 1991-2020): zone 9a.
How late can frost come in St. Joseph?
In half of years the last 32°F night comes after March 13; in one year in ten it comes after April 4. Waiting until April 4 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Louisiana climateThe statewide normals and every place in the state
- Port Gibson, MS16 miles from this station, 65.8°F a year
- Natchez, MS25 miles from this station, 64.2°F a year
- Tallulah, LA30 miles from this station, 66.1°F a year
- Winnsboro, LA31 miles from this station, 65.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made