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Grafton city, Illinois

Official LSAD Designation: Grafton city • Census GEOID: 1730653 • Jersey County

Climate Normals & Weather Observations

30-year climate normals (1991–2020) and weather observations for Grafton city.

Reference Weather Station: ST CHARLES CO AP, MO US (ID: USW00053904) • Located 3.3 miles from community center • Elevation: 132.9 m
Month Average High (°F) Average Low (°F) Mean Temp (°F) Precipitation (in)
January 39.7° 21.9° 30.8° 2.49"
February 45.1° 25.6° 35.4° 1.89"
March 56.4° 34.4° 45.4° 3.08"
April 68.2° 45.1° 56.7° 4.24"
May 77.3° 55.9° 66.6° 4.60"
June 85.9° 64.9° 75.4° 4.55"
July 89.1° 68.1° 78.6° 3.74"
August 87.8° 66.0° 76.9° 3.68"
September 81.2° 57.1° 69.1° 2.97"
October 69.3° 45.8° 57.5° 2.66"
November 55.4° 34.6° 45.0° 3.15"
December 44.1° 27.0° 35.5° 2.35"

Annual Temperature History

2010–2025, completed calendar years only.

NOAA station ST CHARLES CO AP, MO US (ID: USW00053904) • 3.3 miles from community center .

This is the same reference station used for monthly normals.

Annual mean Annual mean of daily highs Annual mean of daily lows
Annual temperature history at ST CHARLES CO AP, MO US Year is the horizontal axis. Annual mean temperature in degrees Fahrenheit is the vertical axis. Dots show recorded years; lines connect consecutive available years only. Missing years are gaps, with no interpolation. Optional dashed lines show annual mean of daily highs and lows. Exact values appear in the data table below. 39.0 47.5 56.0 64.5 73.0 2010 2014 2018 2021 2025 Year Annual mean temperature (°F) 2010: Annual mean 55.7°F 2011: Annual mean 56.3°F 2012: Annual mean 58.6°F 2014: Annual mean 52.9°F 2015: Annual mean 56.1°F 2016: Annual mean 57.7°F 2017: Annual mean 57.8°F 2018: Annual mean 56.2°F 2022: Annual mean 55.9°F 2024: Annual mean 58.6°F 2025: Annual mean 56.4°F 2010: Annual mean of daily highs 66.0°F 2011: Annual mean of daily highs 66.5°F 2012: Annual mean of daily highs 70.1°F 2014: Annual mean of daily highs 63.2°F 2015: Annual mean of daily highs 66.4°F 2016: Annual mean of daily highs 67.8°F 2017: Annual mean of daily highs 69.1°F 2018: Annual mean of daily highs 66.6°F 2022: Annual mean of daily highs 67.0°F 2024: Annual mean of daily highs 69.5°F 2025: Annual mean of daily highs 67.2°F 2010: Annual mean of daily lows 45.4°F 2011: Annual mean of daily lows 46.1°F 2012: Annual mean of daily lows 47.1°F 2014: Annual mean of daily lows 42.6°F 2015: Annual mean of daily lows 45.8°F 2016: Annual mean of daily lows 47.6°F 2017: Annual mean of daily lows 46.5°F 2018: Annual mean of daily lows 45.9°F 2022: Annual mean of daily lows 44.7°F 2024: Annual mean of daily lows 47.6°F 2025: Annual mean of daily lows 45.6°F

Source: NOAA NCEI Global Summary of the Year.

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 55.7 66.0 45.4
2011 56.3 66.5 46.1
2012 58.6 70.1 47.1
2013 Unavailable Unavailable Unavailable
2014 52.9 63.2 42.6
2015 56.1 66.4 45.8
2016 57.7 67.8 47.6
2017 57.8 69.1 46.5
2018 56.2 66.6 45.9
2019 Unavailable Unavailable Unavailable
2020 Unavailable Unavailable Unavailable
2021 Unavailable Unavailable Unavailable
2022 55.9 67.0 44.7
2023 Unavailable Unavailable Unavailable
2024 58.6 69.5 47.6
2025 56.4 67.2 45.6
Source: NOAA NCEI 1991–2020 U.S. Climate Normals, National Weather Service.