This weather has a price Keeping the median Rockwall County home comfortable runs roughly $559 a year in heating and cooling alone. See where it lands in the monthly bill

30-year climate normals

Rockwall County Climate and Weather Averages

Hottest month: August

96.3°

average daily high. The coldest month is January, averaging a low of 35.7°F.

Rockwall County gets 38.42" of precipitation a year, and 30% of it falls in Mar, Apr, May.

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	57.4°	35.7°	2.62"
February	61.7°	39.6°	2.73"
March	69.2°	46.7°	3.69"
April	76.4°	53.8°	3.06"
May	84.4°	63.4°	4.72"
June	91.6°	71.1°	3.40"
July	95.7°	74.3°	2.00"
August	96.3°	74.0°	2.30"
September	89.5°	67.0°	2.74"
October	79.3°	55.9°	4.54"
November	67.7°	45.3°	3.06"
December	59.0°	37.6°	3.56"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 30% falling in the wettest three months (Mar, Apr, May).

January 2.62"

February 2.73"

March 3.69"

April 3.06"

May 4.72"

June 3.40"

July 2.00"

August 2.30"

September 2.74"

October 4.54"

November 3.06"

December 3.56"

Annual total 38.42"

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 2,738

Heating degree days How much heating the climate demands 2,211

Approximate annual cooling cost At 15.91¢/kWh, Texas average $436

Approximate annual electric heating cost Lower where heating is gas rather than electric $123

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 Rockwall County, where electricity is one line of eight.

Common questions

What is the weather like in Rockwall County?

Rockwall County averages a high of 96.3°F in August and a low of 35.7°F in January. Annual precipitation is 38.42 inches, with essentially no snow.

When is the rainy season in Rockwall County?

The wettest stretch is Mar, Apr, May, which accounts for 30% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Rockwall County?

The average daily high in August, the hottest month, is 96.3°F. That drives 2,738 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Rockwall County?

The weather station used for Rockwall County, TERRELL MUNI AP, TX US, reports temperature and precipitation but not snowfall, so there is no snow normal to quote here. Precipitation that falls as snow is still counted in the 38.42 inches above, measured as melted water.

Sources

Temperature, precipitation and snowfall normals: NOAA National Centers for Environmental Information, 1991 to 2020 Monthly Climate Normals, station TERRELL MUNI AP, TX US (USW00053911), 15.6 miles from the county centroid.
Heating and cooling degree days: NOAA, same station and period.
Annual figures on this page are the sum of that station's twelve monthly normals. NOAA also publishes a separately-computed annual normal, which can differ from the monthly sum by a few percent; we use the monthly series because the month-by-month breakdown above has to come from it.
Electricity price: US Energy Information Administration, Electric Power Monthly Table 5.6.A, Texas residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.