30-year climate normals

Grayson County Climate and Weather Averages

Hottest month — August

92.7°

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

Grayson County gets 44.29" of precipitation a year, and 31% of it falls in Apr, May, Jun.

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	52.6°	33.9°	2.52"
February	57.1°	37.2°	2.76"
March	65.2°	45.0°	3.96"
April	72.6°	52.8°	3.87"
May	80.0°	61.6°	5.54"
June	88.1°	69.8°	4.54"
July	92.5°	73.5°	2.90"
August	92.7°	73.0°	2.88"
September	85.4°	66.1°	3.43"
October	75.3°	55.1°	4.77"
November	63.3°	44.1°	3.50"
December	54.2°	36.1°	3.62"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 31% falling in the wettest three months (Apr, May, Jun).

January 2.52"

February 2.76"

March 3.96"

April 3.87"

May 5.54"

June 4.54"

July 2.90"

August 2.88"

September 3.43"

October 4.77"

November 3.50"

December 3.62"

Annual total 44.29"

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 2,261

Heating degree days How much heating the climate demands 2,727

Approximate annual cooling cost At 16.44¢/kWh, Texas average $372

Approximate annual electric heating cost Lower where heating is gas rather than electric $157

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 Grayson County, where electricity is one line of eight.

Common questions

What is the weather like in Grayson County?

Grayson County averages a high of 92.7°F in August and a low of 33.9°F in January. Annual precipitation is 44.29 inches, with essentially no snow.

When is the rainy season in Grayson County?

The wettest stretch is Apr, May, Jun, which accounts for 31% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Grayson County?

The average daily high in August, the hottest month, is 92.7°F. That drives 2,261 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Grayson County?

Effectively no. Measurable snowfall is rare in Grayson County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station SHERMAN, TX US (USC00418274), 5.8 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, Texas residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.