TODAY JUN04
TEMPERATURE81
HUMIDITY66
PRESSURE29.81
WIND COND.
  • 9068Fri20%20%
  • 8663Sat30%
  • 8564Sun
  • 8771Mon
  • 8667Tue20%60%
daynightWeather update from St. Louis Regional Airport at
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Williamson Average Temperature

In the event that the weather data was unavailable for this city, estimates based upon nearby cities were used.
MonthTemp. (min)Temp. (max)Temp. (avg)Precipitation
January23°F38°F29°F3.3"
February24°F40°F31°F3.5"
March36°F55°F44°F3.9"
April45°F67°F55°F9.3"
May55°F75°F64°F5.6"
June64°F84°F73°F7.9"
July66°F86°F76°F5.0"
August65°F86°F74°F5.1"
September57°F80°F67°F6.0"
October46°F68°F56°F5.6"
November36°F54°F44°F3.6"
December28°F42°F34°F3.6"

Did you know?

  • The highest monthly average temperature in Williamson for July is 76 degrees.
  • The lowest monthly average temperature in Williamson for January is 29 degrees.
  • The most monthly precipitation in Williamson occurs in April with 9.3 inches.
  • The air quality index in Williamson is 21% worse than the national average.
  • The pollution index in Williamson is 87% better than the national average.

Compare Williamson, IL Weather To Other Cities

      vs

      Williamson air quality index & pollution index

      In the event that the air quality/pollution data was unavailable for this city, estimates based upon nearby cities were used.
      IndexWilliamsonIllinoisNational
      Air quality index604150
      Pollution index647,2803,347,2955,066,862

      Williamson air quality information

      MeasurementTotal
      Days measured365
      Days with good air quality99
      Days with moderate air quality231
      Days w/ poor A.Q. for sensitive groups33
      Days with unhealthy air quality2

      Williamson air quality information

      PollutantTotal
      Arsenic0.001%
      Benzene0.020%
      Carbon Tetrachloride0.000%
      Lead0.000%
      Mercury0.000%

      Average monthly Williamson temperature with heat index

      Williamson monthly precipitation with daily maximum

      Williamson monthly snow depth with daily maximum

      Williamson monthly wind speed information

      Nearby cities with good air quality

      City, StatePopulationAir Quality IndexNational Avg.
      Butler, IL1543530%
      Taylor Springs, IL4523530%
      Litchfield, IL6,9763530%
      Wilsonville, IL6586020%
      Bunker Hill, IL1,7306020%
      Williamson, IL2336020%

      Cities with similar population

      City, StatePopulationAir Quality IndexNational Avg.
      Houlton, WI2334412%
      Adrian, OR2333628%
      Kelford, NC2333432%
      Handley, WV2333432%
      Megargel, TX2332648%
      Williamson, IL2336020%
      Source: The Williamson, IL weather data displayed above is derived from the NOAA (National Oceanic and Atmospheric). Air quality and pollution data is derived from the EPA (United States Environmental Protection Agency). Air quality and pollution levels measured in a particular area may not be representative of the entire county.