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      Heat Advisory
      until 8:00 PM CDT
      +1 more alert
      Elev 597 ft, 38.781 °N 90.711 °W

      O'Fallon, MO

      O'Fallon Station95°
      Updated: 12:07 PM CDT on September 18, 2026 (GMT -5)
      2 minutes ago
      96°
      72°
      95
      Feels Like 107
      Sunny
      N
      1
      Lower temperature is expected today
      50
      50
      575
      90
      50
      7
      0 mph
      50
      50
      50
      50
      50
      50
      Radar · Now
        Hyper-local data from Weather Underground's network of
        400,000+ personal weather stations worldwide
        Today
        Sat 09/19
        High 96°f
         15% Precip. / 0 in
        Sunny to partly cloudy. A stray shower or thunderstorm is possible. High 96F. Winds light and variable.
        Tonight
        Sat 09/19
        Low 72°f
         24% Precip. / 0 in
        Some clouds. Low 72F. Winds light and variable.
        Tomorrow
        Sun 09/20
        High 96°f71°f
         6% Precip. / 0 in
        Intervals of clouds and sunshine in the morning with more clouds for later in the day. Hot. High 96F. Winds SW at 5 to 10 mph.
        Hourly Forecast
        Now
        91°
        1PM
        93°
        2PM
        95°
        3PM
        96°
        4PM
        95°
        5PM
        94°
        6PM
        91°
        7PM
        87°
        7:05PM
        Sunset
        8PM
        84°
        9PM
        82°
        10PM
        81°
        11PM
        80°
        12AM
        31%
        79°
        1AM
        77°
        2AM
        76°
        3AM
        75°
        4AM
        75°
        5AM
        74°
        6AM
        74°
        6:48AM
        Sunrise
        7AM
        73°
        8AM
        76°
        9AM
        81°
        10AM
        84°
        11AM
        88°
        12PM
        91°
        Precipitation
        31%
        Pollen
        Ragweed Pollen
        High
        Air Quality
        60
        Moderate
        UV Index
        7
        High
        Additional Conditions
        1. Pressure 30.09 in
        2. Visibility 10 miles
        3. Clouds Clear
        4. Dew Point74°F
        5. Humidity 57%
        6. Rainfall 0.01 in
        7. Snow Depth 0 in
         KSUS Station History
        Almanac for September 18, 2026
        1. Forecast Average Record
        2. Temperature
        3. High 96°F 79°F 91°F 2018
        4. Low 72°F 56°F 40°F 1981
        5. Rain/Snow Depth
        6. Precipitation 0 in 3.2 in -
        7. Snow 0 in 0 in -
        Almanac for September 19, 2026
        1. Forecast Average Record
        2. Temperature
        3. High 96°F 79°F 93°F
        4. Low 72°F 56°F 38°F
        Astronomy
        1. Sun Rise Set
        2. Actual Time 6:47 AM 7:06 PM
        3. Civil Twilight 6:20 AM 7:32 PM
        4. Nautical Twilight 5:49 AM 8:03PM
        5. Astronomical Twilight 5:17 AM 8:35 PM
        1. Length of Visible Light 13h 12m
        2. Length of Day 12h 19m
        3. Tomorrow will be 2 minutes 31 seconds shorter
        1. Moon 2:33 PM 11:27 PM
        2. First Quarter49% of the Moon is Illuminated
        Sep 18
        Waxing Half First Qtr
        Sep 26
        Full Moon
        Oct 3
        Waning Half Last Qtr
        Oct 10
        New Moon
        Precipitation
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