30-year climate normals

Dorchester County Climate and Weather Averages

Hottest month — July

90.1°

average daily high. The coldest month is January, averaging a low of 34.5°F.

Dorchester County gets 52.7" of precipitation a year, and 36% 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	58.2°	34.5°	3.63"
February	61.9°	37.0°	3.27"
March	68.5°	42.2°	3.89"
April	75.6°	49.5°	3.45"
May	82.3°	59.1°	3.52"
June	87.2°	67.2°	5.60"
July	90.1°	70.9°	6.78"
August	89.7°	70.4°	6.17"
September	84.7°	64.8°	5.88"
October	76.6°	53.0°	4.12"
November	67.7°	42.2°	2.97"
December	61.3°	37.4°	3.42"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 36% falling in the wettest three months (Jul, Aug, Sep).

January 3.63"

February 3.27"

March 3.89"

April 3.45"

May 3.52"

June 5.60"

July 6.78"

August 6.17"

September 5.88"

October 4.12"

November 2.97"

December 3.42"

Annual total 52.7"

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 1,988

Heating degree days How much heating the climate demands 2,385

Approximate annual cooling cost At 16.18¢/kWh, South Carolina average $322

Approximate annual electric heating cost Lower where heating is gas rather than electric $135

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 Dorchester County, where electricity is one line of eight.

Common questions

What is the weather like in Dorchester County?

Dorchester County averages a high of 90.1°F in July and a low of 34.5°F in January. Annual precipitation is 52.7 inches, with essentially no snow.

When is the rainy season in Dorchester County?

The wettest stretch is Jul, Aug, Sep, which accounts for 36% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Dorchester County?

The average daily high in July, the hottest month, is 90.1°F. That drives 1,988 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Dorchester County?

Effectively no. Measurable snowfall is rare in Dorchester County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station SUMMERVILLE 4W, SC US (USC00388426), 10.5 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.