FAIRFIELD, IL

Overview:
Situated in rural southeastern Illinois, Fairfield supports a boasting agriculture industry, mainly growing corn and soybeans.

The average high temperature is 65.7°F, but that value can climb into the 80s during the summer months. The average annual precipitation is 44.1inches, with March through May experiencing the highest precipitation totals. Thunderstorms are common during late summer and are capable of producing heavy precipitation. Winters are cloudy with the sun only shining 44% of the time. Several days per year have 1inch of snowfall on the ground.

State/ Province ID: IL

Station ID: C00112931

Directory Name: FAIRFIELD_RADIO_WFIW__IL_C00112931

Elevation: 131.10m

The resources presented here were developed in cooperation with the Office of the Michigan State Climatologist using data from the National Centers for Environmental Information. For more information regarding our data sources, quality control, and methodology, please see our Historical Climatologies: Quality Control reference guide.

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Recent Climate Summary, 1991-2020


Average Temperature	55.8°F13.2°C
Average Low Temperature	45.1°F7.3°C
Average High Temperature	66.5°19.2°C
Days/Year that exceed 90°F	35.3
Days/Year that fall below 32°F	91.1
Lowest Annual Average Temperature	53.2°F11.8°C
Highest Annual Average Temperature	59.6°F15.3°C
Average Annual Total Precipitation	45.4 in115.2 cm
Lowest Annual Precipitation Total	31.7 in80.6 cm
Highest Annual Precipitation Total	68.8 in174.8 cm
Days/Year that exceed 1.25" of Precipitation	7.8

Temperature

Click on the following links to be taken to the corresponding portion of the page.

Monthly Average Temperature
How Temperatures are Changing
- Changes in Average Temperature – Includes a summary table of the average annual and seasonal temperature changes, and time series graphs of how the annual low, average, and high temperatures compare to the long term average plotted for every year on record.
- Cold Temperatures – View time series plots of the number of days per year below 32°F and the number of heating degree days per year to see how cold days are changing.
- Hot Temperatures – View time series plots of the number of days per year above 90°F and the number of cooling degree days per year to see how hot days are changing.
- Growing Season Changes – View a time series of the annual number of days in the freeze-free period.

Monthly Average Temperature

Changes in Average Temperature, 1951-2025.


	°F°C
Annual average temperature	1.30.7
Winter average temperature	0.90.5
Spring average temperature	2.01.1
Summer average temperature	1.20.7
Fall average temperature	1.40.8

Annual High and Low Temperature Departure

Cold Temperatures

¹Heating Degree Days (HDDs) are indexed units, not actual days, that roughly describe the demand to heat a building. HDDs accumulate on days colder than 65°F when heating is required. Every degree below 65°F is added to the annual total for an annual HDD value, which is plotted in the figure.

Hot Temperatures

²Cooling Degree Days (CDDs) are indexed units, not actual days, that roughly describe the demand to cool a building. CDDs accumulate on days warmer than 65°F when cooling is required. Every degree above 65°F is added to the annual total for an annual CDD value, which is plotted in the figure.

Growing Season Changes

Precipitation