30-year climate normals

Marion County Climate and Weather Averages

Hottest month — July

90.5°

average daily high. The coldest month is January, averaging a low of 33.9°F.

Marion County gets 49.27" of precipitation a year, and 34% of it falls in Jul, Aug, Sep.

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	56.1°	33.9°	3.51"
February	59.8°	36.5°	3.22"
March	66.9°	42.4°	3.51"
April	75.4°	49.3°	3.43"
May	82.1°	59.0°	3.62"
June	87.6°	67.4°	4.96"
July	90.5°	71.0°	5.23"
August	88.9°	69.6°	5.54"
September	84.2°	63.8°	5.97"
October	75.8°	51.6°	3.26"
November	66.1°	42.2°	3.33"
December	59.4°	36.6°	3.69"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 34% falling in the wettest three months (Jul, Aug, Sep).

January 3.51"

February 3.22"

March 3.51"

April 3.43"

May 3.62"

June 4.96"

July 5.23"

August 5.54"

September 5.97"

October 3.26"

November 3.33"

December 3.69"

Annual total 49.27"

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 1,944

Heating degree days How much heating the climate demands 2,582

Approximate annual cooling cost At 16.18¢/kWh, South Carolina average $315

Approximate annual electric heating cost Lower where heating is gas rather than electric $146

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 Marion County, where electricity is one line of eight.

Common questions

What is the weather like in Marion County?

Marion County averages a high of 90.5°F in July and a low of 33.9°F in January. Annual precipitation is 49.27 inches, with essentially no snow.

When is the rainy season in Marion County?

The wettest stretch is Jul, Aug, Sep, which accounts for 34% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Marion County?

The average daily high in July, the hottest month, is 90.5°F. That drives 1,944 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Marion County?

Effectively no. Measurable snowfall is rare in Marion County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station MARION, SC US (USC00385509), 6 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, South Carolina residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.