National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

Decatur Airport (KDEC)

Lat: 39.83°NLon: 88.87°WElev: 670ft.

Fair

75°F

24°C

Humidity 90%
Wind Speed Calm
Barometer 30.06 in (1017.2 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Last update 14 Jul 10:54 pm CDT
Extended Forecast for

Niantic IL

  • Tonight

    Tonight: Partly cloudy, with a low around 70. Calm wind.

    Low: 70 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A 50 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 86. Southeast wind around 6 mph.

    High: 86 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 72. South southeast wind around 6 mph becoming calm in the evening.

    Low: 72 °F

    Slight Chance
    T-storms

  • Wednesday

    Wednesday: Mostly sunny, with a high near 89. Heat index values as high as 100. Southwest wind 5 to 8 mph.

    High: 89 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 73. South southwest wind around 6 mph. Chance of precipitation is 30%.

    Low: 73 °F

    Chance
    T-storms

  • Thursday

    Thursday: A 50 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 87. West wind 7 to 10 mph.

    High: 87 °F

    Mostly Sunny
    then Chance
    T-storms

  • Thursday Night

    Thursday Night: A 40 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 68. Northwest wind around 7 mph becoming north northeast after midnight.

    Low: 68 °F

    Chance
    T-storms

  • Friday

    Friday: Partly sunny, with a high near 83.

    High: 83 °F

    Partly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 70.

    Low: 70 °F

    Partly Cloudy

Detailed Forecast

Tonight
Partly cloudy, with a low around 70. Calm wind.
Tuesday
A 50 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 86. Southeast wind around 6 mph.
Tuesday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 72. South southeast wind around 6 mph becoming calm in the evening.
Wednesday
Mostly sunny, with a high near 89. Heat index values as high as 100. Southwest wind 5 to 8 mph.
Wednesday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 73. South southwest wind around 6 mph. Chance of precipitation is 30%.
Thursday
A 50 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 87. West wind 7 to 10 mph.
Thursday Night
A 40 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 68. Northwest wind around 7 mph becoming north northeast after midnight.
Friday
Partly sunny, with a high near 83.
Friday Night
Partly cloudy, with a low around 70.
Saturday
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 88.
Saturday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 72.
Sunday
A chance of showers and thunderstorms. Mostly sunny, with a high near 88.
Sunday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 70.
Monday
A chance of showers and thunderstorms. Mostly sunny, with a high near 88.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Niantic IL
 39.85°N 89.17°W (Elev. 600 ft)
Last Update:
10:41 pm CDT Jul 14, 2025
Forecast Valid:
11pm CDT Jul 14, 2025-6pm CDT Jul 21, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation