30-year climate normals

Johnson County Climate and Weather Averages

Hottest month — July

89.8°

average daily high. The coldest month is January, averaging a low of 18.4°F.

Johnson County gets 42.11" of precipitation a year, and 37% 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	40.4°	18.4°	1.18"
February	45.1°	22.2°	1.80"
March	56.7°	32.0°	3.01"
April	67.2°	42.3°	4.32"
May	76.4°	53.4°	5.52"
June	85.0°	62.8°	5.36"
July	89.8°	66.8°	4.91"
August	88.8°	64.7°	4.08"
September	81.3°	55.4°	4.12"
October	69.4°	43.4°	3.31"
November	55.9°	32.6°	2.55"
December	44.7°	23.1°	1.95"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 37% falling in the wettest three months (May, Jun, Jul).

January 1.18"

February 1.80"

March 3.01"

April 4.32"

May 5.52"

June 5.36"

July 4.91"

August 4.08"

September 4.12"

October 3.31"

November 2.55"

December 1.95"

Annual total 42.11"

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 1,356

Heating degree days How much heating the climate demands 4,997

Approximate annual cooling cost At 13.68¢/kWh, Missouri average $186

Approximate annual electric heating cost Lower where heating is gas rather than electric $239

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 Johnson County, where electricity is one line of eight.

Common questions

What is the weather like in Johnson County?

Johnson County averages a high of 89.8°F in July and a low of 18.4°F in January. Annual precipitation is 42.11 inches, with essentially no snow.

When is the rainy season in Johnson County?

The wettest stretch is May, Jun, Jul, which accounts for 37% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Johnson County?

The average daily high in July, the hottest month, is 89.8°F. That drives 1,356 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Johnson County?

Effectively no. Measurable snowfall is rare in Johnson County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station WARRENSBURG 4NW, MO US (USC00238712), 3 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, Missouri residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.