30-year climate normals

Chatham County Climate and Weather Averages

Hottest month — July

89.6°

average daily high. The coldest month is January, averaging a low of 31.7°F.

Chatham County gets 43.56" of precipitation a year, and 28% 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	51.2°	31.7°	3.39"
February	54.8°	33.8°	2.75"
March	62.7°	40.1°	3.94"
April	72.2°	48.1°	3.56"
May	79.1°	57.0°	3.46"
June	86.3°	65.3°	4.36"
July	89.6°	69.3°	4.13"
August	87.8°	67.9°	3.81"
September	81.9°	62.2°	4.41"
October	72.3°	49.6°	3.20"
November	62.4°	39.5°	3.20"
December	54.2°	34.5°	3.35"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 28% falling in the wettest three months (Jul, Aug, Sep).

January 3.39"

February 2.75"

March 3.94"

April 3.56"

May 3.46"

June 4.36"

July 4.13"

August 3.81"

September 4.41"

October 3.20"

November 3.20"

December 3.35"

Annual total 43.56"

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 1,652

Heating degree days How much heating the climate demands 3,239

Approximate annual cooling cost At 15.09¢/kWh, North Carolina average $249

Approximate annual electric heating cost Lower where heating is gas rather than electric $171

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 Chatham County, where electricity is one line of eight.

Common questions

What is the weather like in Chatham County?

Chatham County averages a high of 89.6°F in July and a low of 31.7°F in January. Annual precipitation is 43.56 inches, with essentially no snow.

When is the rainy season in Chatham County?

The wettest stretch is Jul, Aug, Sep, which accounts for 28% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Chatham County?

The average daily high in July, the hottest month, is 89.6°F. That drives 1,652 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Chatham County?

Effectively no. Measurable snowfall is rare in Chatham County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station CHAPEL HILL WILLIAMS AP, NC US (USW00093785), 18.9 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, North Carolina residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.