30-year climate normals

St. James Parish Climate and Weather Averages

Hottest month — July

91.6°

average daily high. The coldest month is January, averaging a low of 42.9°F.

St. James Parish gets 67.21" of precipitation a year, and 32% of it falls in May, Jun, Jul.

Temperature through the year

Each bar spans the average daily low to the average daily high for that month.

Month	Avg high	Avg low	Precip
January	62.3°	42.9°	5.89"
February	66.7°	46.6°	4.44"
March	72.4°	52.1°	4.90"
April	78.8°	58.3°	5.54"
May	84.9°	66.2°	5.85"
June	89.3°	72.6°	8.62"
July	91.6°	74.7°	7.08"
August	91.6°	74.7°	5.74"
September	88.3°	71.0°	5.75"
October	81.1°	60.8°	4.14"
November	71.2°	50.6°	4.28"
December	64.7°	45.5°	4.98"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 32% falling in the wettest three months (May, Jun, Jul).

January 5.89"

February 4.44"

March 4.90"

April 5.54"

May 5.85"

June 8.62"

July 7.08"

August 5.74"

September 5.75"

October 4.14"

November 4.28"

December 4.98"

Annual total 67.21"

What this climate costs you

Degree days measure how hard a building has to work to stay comfortable. They are the reason two identical houses have very different power bills, and they are the link between the weather here and what you pay every month.

Cooling degree days How much air conditioning the climate demands 2,870

Heating degree days How much heating the climate demands 1,342

Approximate annual cooling cost At 14.15¢/kWh, Louisiana average $406

Approximate annual electric heating cost Lower where heating is gas rather than electric $66

These are rough planning figures from degree days and the state electricity price, not a bill estimate. House size, insulation and fuel type move them a lot. See the full cost of owning a home in St. James Parish, where electricity is one line of eight.

Common questions

What is the weather like in St. James Parish?

St. James Parish averages a high of 91.6°F in July and a low of 42.9°F in January. Annual precipitation is 67.21 inches, with essentially no snow.

When is the rainy season in St. James Parish?

The wettest stretch is May, Jun, Jul, which accounts for 32% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in St. James Parish?

The average daily high in July, the hottest month, is 91.6°F. That drives 2,870 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in St. James Parish?

Effectively no. Measurable snowfall is rare in St. James Parish.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station RESERVE, LA US (USC00167767), 13 miles from the county centroid.
Heating and cooling degree days — NOAA, same station and period.
Electricity price — US Energy Information Administration, Electric Power Monthly Table 5.6.A, Louisiana residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.