30-year climate normals

Scott County Climate and Weather Averages

Hottest month — July

86.8°

average daily high. The coldest month is January, averaging a low of 17.8°F.

Scott County gets 40.4" of precipitation a year, and 35% 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	35.7°	17.8°	2.26"
February	41.1°	21.3°	2.14"
March	52.5°	30.5°	3.06"
April	65.1°	41.0°	4.40"
May	74.9°	52.1°	4.81"
June	83.6°	61.8°	4.99"
July	86.8°	65.1°	3.97"
August	86.1°	62.8°	3.47"
September	80.1°	53.8°	3.03"
October	67.8°	42.5°	3.09"
November	52.7°	31.6°	2.75"
December	40.9°	23.3°	2.43"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 35% falling in the wettest three months (Apr, May, Jun).

January 2.26"

February 2.14"

March 3.06"

April 4.40"

May 4.81"

June 4.99"

July 3.97"

August 3.47"

September 3.03"

October 3.09"

November 2.75"

December 2.43"

Annual total 40.4"

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 1,131

Heating degree days How much heating the climate demands 5,485

Approximate annual cooling cost At 23.85¢/kWh, Illinois average $270

Approximate annual electric heating cost Lower where heating is gas rather than electric $458

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 Scott County, where electricity is one line of eight.

Common questions

What is the weather like in Scott County?

Scott County averages a high of 86.8°F in July and a low of 17.8°F in January. Annual precipitation is 40.4 inches, with essentially no snow.

When is the rainy season in Scott County?

The wettest stretch is Apr, May, Jun, which accounts for 35% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Scott County?

The average daily high in July, the hottest month, is 86.8°F. That drives 1,131 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Scott County?

Effectively no. Measurable snowfall is rare in Scott County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station WINCHESTER, IL US (USC00119331), 1.3 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, Illinois residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.