This weather has a price Keeping the median Union County home comfortable runs roughly $542 a year in heating and cooling alone. See where it lands in the monthly bill

30-year climate normals

Union County Climate and Weather Averages

Hottest month: July

84.7°

average daily high. The coldest month is January, averaging a low of 10.6°F.

Union County gets 37.89" of precipitation a year, and 39% 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
January	30.5°	10.6°	1.04"
February	35.1°	13.8°	1.46"
March	48.7°	25.5°	2.53"
April	61.2°	36.1°	3.74"
May	71.3°	48.8°	5.15"
June	80.9°	59.4°	5.17"
July	84.7°	63.2°	4.46"
August	83.0°	60.7°	4.23"
September	76.4°	51.6°	3.70"
October	64.1°	39.3°	2.79"
November	48.4°	26.2°	2.14"
December	35.7°	16.0°	1.48"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 39% falling in the wettest three months (May, Jun, Jul).

January 1.04"

February 1.46"

March 2.53"

April 3.74"

May 5.15"

June 5.17"

July 4.46"

August 4.23"

September 3.70"

October 2.79"

November 2.14"

December 1.48"

Annual total 37.89"

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 831

Heating degree days How much heating the climate demands 6,696

Approximate annual cooling cost At 17.06¢/kWh, Iowa average $142

Approximate annual electric heating cost Lower where heating is gas rather than electric $400

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 84.7°F in July and a low of 10.6°F in January. Annual precipitation is 37.89 inches, with essentially no snow.

When is the rainy season in Union County?

The wettest stretch is May, Jun, Jul, which accounts for 39% 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 84.7°F. That drives 831 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Union County?

The weather station used for Union County, CRESTON 2 SW, IA 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 37.89 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 CRESTON 2 SW, IA US (USC00131962), 7.8 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, Iowa residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.