30-year climate normals

Union County Climate and Weather Averages

Hottest month — July

84.9°

average daily high. The coldest month is January, averaging a low of 20.6°F.

Union County gets 40.48" of precipitation a year and 24" of snow, and 33% of it falls in May, Jun, Jul.

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	Snow
January	35.0°	20.6°	2.68"	7.0"
February	38.9°	22.9°	2.29"	6.6"
March	49.6°	30.8°	3.02"	4.1"
April	63.0°	41.0°	3.86"	0.1"
May	73.6°	51.8°	4.52"	0.0"
June	81.7°	60.8°	4.85"	0.0"
July	84.9°	64.4°	4.15"	0.0"
August	83.5°	62.4°	3.41"	0.0"
September	77.5°	54.7°	3.20"	0.0"
October	65.0°	43.8°	2.72"	0.0"
November	50.9°	33.7°	2.90"	0.7"
December	39.6°	26.1°	2.88"	5.5"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 33% falling in the wettest three months (May, Jun, Jul).

January 2.68"

February 2.29"

March 3.02"

April 3.86"

May 4.52"

June 4.85"

July 4.15"

August 3.41"

September 3.20"

October 2.72"

November 2.90"

December 2.88"

Annual total 40.48"

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 968

Heating degree days How much heating the climate demands 5,546

Approximate annual cooling cost At 19.52¢/kWh, Ohio average $189

Approximate annual electric heating cost Lower where heating is gas rather than electric $379

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 Union County, where electricity is one line of eight.

Common questions

What is the weather like in Union County?

Union County averages a high of 84.9°F in July and a low of 20.6°F in January. Annual precipitation is 40.48 inches, including 24 inches of snow.

When is the rainy season in Union County?

The wettest stretch is May, Jun, Jul, which accounts for 33% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Union County?

The average daily high in July, the hottest month, is 84.9°F. That drives 968 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Union County?

Yes. Union County averages 24 inches of snow a year.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station MARYSVILLE, OH US (USC00334979), 8.8 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, Ohio residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.