This weather has a price Keeping the median Sangamon County home comfortable runs roughly $580 a year in heating and cooling alone. See where it lands in the monthly bill

30-year climate normals

Sangamon County Climate and Weather Averages

Hottest month: July

85.5°

average daily high. The coldest month is January, averaging a low of 18.6°F.

Sangamon County gets 40.45" of precipitation a year, and 36% 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	35.8°	18.6°	2.19"
February	41.1°	21.6°	2.20"
March	52.3°	30.7°	2.96"
April	64.5°	41.1°	4.13"
May	73.5°	53.0°	5.14"
June	82.7°	62.6°	5.04"
July	85.5°	65.9°	4.38"
August	83.9°	63.7°	2.86"
September	77.9°	55.5°	3.06"
October	66.3°	43.7°	3.10"
November	52.7°	32.8°	3.10"
December	41.3°	23.8°	2.29"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 36% falling in the wettest three months (May, Jun, Jul).

January 2.19"

February 2.20"

March 2.96"

April 4.13"

May 5.14"

June 5.04"

July 4.38"

August 2.86"

September 3.06"

October 3.10"

November 3.10"

December 2.29"

Annual total 40.45"

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 1,094

Heating degree days How much heating the climate demands 5,455

Approximate annual cooling cost At 19.32¢/kWh, Illinois average $211

Approximate annual electric heating cost Lower where heating is gas rather than electric $369

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 Sangamon County, where electricity is one line of eight.

Common questions

What is the weather like in Sangamon County?

Sangamon County averages a high of 85.5°F in July and a low of 18.6°F in January. Annual precipitation is 40.45 inches, with essentially no snow.

When is the rainy season in Sangamon County?

The wettest stretch is May, Jun, Jul, which accounts for 36% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Sangamon County?

The average daily high in July, the hottest month, is 85.5°F. That drives 1,094 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Sangamon County?

The weather station used for Sangamon County, SPRINGFIELD #2, IL 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 40.45 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 SPRINGFIELD #2, IL US (USC00118186), 2.9 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, Illinois residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.