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Troy city, Illinois

Official LSAD Designation: Troy city • Census GEOID: 1776199 • Madison County

Climate Normals & Weather Observations

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

Reference Weather Station: BELLEVILLE SIU RSCH, IL US (ID: USW00013802) • Located 14.5 miles from community center • Elevation: 137.2 m
Month Average High (°F) Average Low (°F) Mean Temp (°F) Precipitation (in)
January 42.9° 24.3° 33.6° 2.56"
February 48.6° 28.0° 38.3° 2.16"
March 59.2° 36.3° 47.8° 3.44"
April 70.6° 46.0° 58.3° 4.90"
May 79.1° 56.3° 67.7° 5.05"
June 87.3° 64.5° 75.9° 4.62"
July 90.2° 67.8° 79.0° 4.03"
August 89.1° 65.3° 77.2° 3.92"
September 83.3° 56.9° 70.1° 3.35"
October 72.6° 46.7° 59.7° 3.12"
November 58.1° 36.9° 47.5° 3.60"
December 46.3° 28.3° 37.3° 2.61"

Annual Temperature History

2010–2025, completed calendar years only.

NOAA station BELLEVILLE SIU RSCH, IL US (ID: USW00013802) • 14.5 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 BELLEVILLE SIU RSCH, IL 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. 40.0 49.0 58.0 67.0 76.0 2010 2014 2018 2021 2025 Year Annual mean temperature (°F) 2010: Annual mean 57.5°F 2011: Annual mean 58.7°F 2012: Annual mean 60.5°F 2013: Annual mean 56.4°F 2014: Annual mean 55.2°F 2015: Annual mean 58.2°F 2016: Annual mean 59.5°F 2017: Annual mean 59.9°F 2018: Annual mean 57.8°F 2019: Annual mean 57.0°F 2024: Annual mean 57.5°F 2025: Annual mean 58.1°F 2010: Annual mean of daily highs 68.6°F 2011: Annual mean of daily highs 69.6°F 2012: Annual mean of daily highs 73.0°F 2013: Annual mean of daily highs 67.5°F 2014: Annual mean of daily highs 66.5°F 2015: Annual mean of daily highs 69.0°F 2016: Annual mean of daily highs 70.4°F 2017: Annual mean of daily highs 71.9°F 2018: Annual mean of daily highs 68.8°F 2019: Annual mean of daily highs 67.8°F 2024: Annual mean of daily highs 68.2°F 2025: Annual mean of daily highs 68.3°F 2010: Annual mean of daily lows 46.4°F 2011: Annual mean of daily lows 47.9°F 2012: Annual mean of daily lows 48.1°F 2013: Annual mean of daily lows 45.4°F 2014: Annual mean of daily lows 43.9°F 2015: Annual mean of daily lows 47.4°F 2016: Annual mean of daily lows 48.5°F 2017: Annual mean of daily lows 47.9°F 2018: Annual mean of daily lows 46.8°F 2019: Annual mean of daily lows 46.2°F 2024: Annual mean of daily lows 46.7°F 2025: Annual mean of daily lows 48.0°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 57.5 68.6 46.4
2011 58.7 69.6 47.9
2012 60.5 73.0 48.1
2013 56.4 67.5 45.4
2014 55.2 66.5 43.9
2015 58.2 69.0 47.4
2016 59.5 70.4 48.5
2017 59.9 71.9 47.9
2018 57.8 68.8 46.8
2019 57.0 67.8 46.2
2020 Unavailable Unavailable Unavailable
2021 Unavailable Unavailable Unavailable
2022 Unavailable Unavailable Unavailable
2023 Unavailable Unavailable Unavailable
2024 57.5 68.2 46.7
2025 58.1 68.3 48.0
Source: NOAA NCEI 1991–2020 U.S. Climate Normals, National Weather Service.