TODAY JUN02
TEMPERATURE73
HUMIDITY61
PRESSURE30.09
WIND COND.150 6.9
  • 9069Tue
  • 8970Wed50%
  • 8870Thu50%50%
  • 9070Fri30%30%
  • 8868Sat
daynightWeather update from St. Louis Regional Airport at
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Alton 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
January24°F41°F31°F3.4"
February25°F43°F33°F3.7"
March38°F57°F46°F3.1"
April47°F68°F56°F6.6"
May56°F76°F65°F6.1"
June65°F85°F75°F3.5"
July67°F87°F77°F7.3"
August66°F86°F75°F6.8"
September58°F80°F68°F4.4"
October47°F68°F57°F6.7"
November36°F56°F45°F4.9"
December28°F43°F35°F6.3"

Did you know?

  • The highest monthly average temperature in Alton for July is 77 degrees.
  • The lowest monthly average temperature in Alton for January is 31 degrees.
  • The most monthly precipitation in Alton occurs in July with 7.3 inches.
  • The air quality index in Alton is 21% worse than the national average.
  • The pollution index in Alton is 67% worse than the national average.

Compare Alton, IL Weather To Other Cities

      vs

      Alton 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.
      IndexAltonIllinoisNational
      Air quality index604150
      Pollution index8,473,0503,347,2955,066,862

      Alton 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

      Alton air quality information

      PollutantTotal
      Arsenic0.020%
      Benzene0.070%
      Carbon Tetrachloride0.020%
      Lead0.010%
      Mercury0.010%

      Average monthly Alton temperature with heat index

      Alton monthly precipitation with daily maximum

      Alton monthly snow depth with daily maximum

      Alton monthly wind speed information

      Nearby cities with good air quality

      City, StatePopulationAir Quality IndexNational Avg.
      Maryland Heights, MO27,3596020%
      Norwood Court, MO8296020%
      Pasadena Park, MO5156020%
      St. Ann, MO12,9316020%
      Uplands Park, MO3886020%
      Alton, IL27,1756020%

      Cities with similar population

      City, StatePopulationAir Quality IndexNational Avg.
      Thomasville, NC27,1784020%
      Isla Vista, CA27,1794412%
      Imperial Beach, CA27,1806122%
      Anderson, SC27,2063138%
      New London, CT27,2184412%
      Alton, IL27,1756020%
      Source: The Alton, 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.