Janesville CDP, Illinois

Official LSAD Designation: Janesville CDP • Census GEOID: 1738232 • Coles County

Climate Normals & Weather Observations

30-year climate normals (1991–2020) and weather observations for Janesville CDP.

Reference Weather Station: MATTOON COLES CO AP, IL US (ID: USW00053802) • Located 7.4 miles from community center • Elevation: 219.8 m

Month	Average High (°F)	Average Low (°F)	Mean Temp (°F)	Precipitation (in)
January	35.4°	20.3°	27.8°	2.04"
February	40.3°	23.7°	32.0°	1.81"
March	52.2°	33.0°	42.6°	2.22"
April	64.0°	43.2°	53.6°	4.14"
May	73.9°	54.0°	63.9°	3.86"
June	82.7°	62.8°	72.8°	4.72"
July	85.6°	65.7°	75.7°	3.96"
August	84.2°	63.5°	73.9°	2.42"
September	78.7°	56.1°	67.4°	2.85"
October	65.9°	45.3°	55.6°	3.11"
November	51.3°	34.6°	42.9°	3.03"
December	40.0°	26.0°	33.0°	1.84"

2010–2025, completed calendar years only.

NOAA station MATTOON COLES CO AP, IL US (ID: USW00053802) • 7.4 miles from community center .

This is the same reference station used for monthly normals.

Show annual mean of daily highs and lows

Annual mean Annual mean of daily highs Annual mean of daily lows

Annual temperature data table (°F)

Annual station temperatures, 2010–2025. Unavailable means no reported value.
Year	Annual mean (°F)	Annual mean of daily highs (°F)	Annual mean of daily lows (°F)
2010	53.5	63.0	43.9
2011	54.3	63.4	45.1
2012	56.4	66.7	46.0
2013	Unavailable	Unavailable	42.8
2014	50.2	59.4	41.0
2015	53.5	63.0	44.1
2016	55.1	64.3	45.9
2017	55.3	65.1	45.5
2018	53.3	62.6	44.1
2019	53.2	62.4	44.1
2020	54.5	63.7	45.3
2021	54.8	64.0	45.7
2022	53.4	63.1	43.7
2023	55.5	65.7	45.4
2024	Unavailable	65.7	Unavailable
2025	54.2	64.0	44.4

Source: NOAA NCEI 1991–2020 U.S. Climate Normals, National Weather Service.