30-year climate normals

Decatur County Climate and Weather Averages

Hottest month — July

85.4°

average daily high. The coldest month is January, averaging a low of 15.6°F.

Decatur County gets 37.38" of precipitation a year, and 38% 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	33.1°	15.6°	1.04"
February	38.1°	19.6°	1.35"
March	50.8°	30.7°	2.20"
April	62.5°	41.4°	4.25"
May	72.0°	52.5°	5.14"
June	81.5°	62.2°	4.81"
July	85.4°	66.2°	4.11"
August	83.8°	63.9°	4.38"
September	76.5°	55.2°	3.71"
October	64.0°	43.3°	2.82"
November	49.7°	31.1°	2.09"
December	37.7°	20.9°	1.48"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 38% falling in the wettest three months (Apr, May, Jun).

January 1.04"

February 1.35"

March 2.20"

April 4.25"

May 5.14"

June 4.81"

July 4.11"

August 4.38"

September 3.71"

October 2.82"

November 2.09"

December 1.48"

Annual total 37.38"

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 1,038

Heating degree days How much heating the climate demands 5,895

Approximate annual cooling cost At 14.14¢/kWh, Iowa average $147

Approximate annual electric heating cost Lower where heating is gas rather than electric $292

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 Decatur County, where electricity is one line of eight.

Common questions

What is the weather like in Decatur County?

Decatur County averages a high of 85.4°F in July and a low of 15.6°F in January. Annual precipitation is 37.38 inches, with essentially no snow.

When is the rainy season in Decatur County?

The wettest stretch is Apr, May, Jun, which accounts for 38% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Decatur County?

The average daily high in July, the hottest month, is 85.4°F. That drives 1,038 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Decatur County?

Effectively no. Measurable snowfall is rare in Decatur County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station LAMONI MUNI AP, IA US (USW00094991), 9.4 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, Iowa residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.