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

50°F

10°C

Humidity 61%
Wind Speed E 10 mph
Barometer 30.09 in (1018.9 mb)
Dewpoint 37°F (3°C)
Visibility 10.00 mi
Wind Chill46°F (8°C)
Last update 13 May 11:54 pm CDT
Extended Forecast for

Niantic IL

  • Overnight

    Overnight: Clear, with a low around 42. Light and variable wind becoming east around 5 mph.

    Low: 42 °F

    Clear

  • Thursday

    Thursday: Sunny, with a high near 72. Calm wind becoming south southeast around 5 mph in the afternoon.

    High: 72 °F

    Sunny

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm, mainly after 4am. Increasing clouds, with a low around 53. South southeast wind 8 to 11 mph, with gusts as high as 18 mph. Chance of precipitation is 70%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 53 °F

    Partly Cloudy
    then Showers
    Likely

  • Friday

    Friday: Showers likely before 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 77. Breezy, with a south southeast wind 16 to 23 mph, with gusts as high as 29 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

    High: 77 °F

    Showers
    Likely and
    Breezy

  • Friday Night

    Friday Night: A 40 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 63. South wind 8 to 14 mph, with gusts as high as 21 mph.

    Low: 63 °F

    Partly Cloudy
    then Chance
    T-storms

  • Saturday

    Saturday: Showers and thunderstorms likely, mainly after 1pm. Partly sunny, with a high near 81. South southwest wind 8 to 13 mph, with gusts as high as 17 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 81 °F

    T-storms
    Likely

  • Saturday Night

    Saturday Night: Showers and thunderstorms likely before 1am. Mostly cloudy, with a low around 63. South southwest wind around 9 mph becoming southeast after midnight. Winds could gust as high as 15 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 63 °F

    T-storms
    Likely

  • Sunday

    Sunday: Mostly sunny, with a high near 84. Breezy.

    High: 84 °F

    Mostly Sunny
    then Partly
    Sunny and
    Breezy

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 68. Breezy.

    Low: 68 °F

    Partly Cloudy
    and Breezy
    then Mostly
    Clear

Detailed Forecast

Overnight
Clear, with a low around 42. Light and variable wind becoming east around 5 mph.
Thursday
Sunny, with a high near 72. Calm wind becoming south southeast around 5 mph in the afternoon.
Thursday Night
Showers likely and possibly a thunderstorm, mainly after 4am. Increasing clouds, with a low around 53. South southeast wind 8 to 11 mph, with gusts as high as 18 mph. Chance of precipitation is 70%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday
Showers likely before 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 77. Breezy, with a south southeast wind 16 to 23 mph, with gusts as high as 29 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.
Friday Night
A 40 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 63. South wind 8 to 14 mph, with gusts as high as 21 mph.
Saturday
Showers and thunderstorms likely, mainly after 1pm. Partly sunny, with a high near 81. South southwest wind 8 to 13 mph, with gusts as high as 17 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday Night
Showers and thunderstorms likely before 1am. Mostly cloudy, with a low around 63. South southwest wind around 9 mph becoming southeast after midnight. Winds could gust as high as 15 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday
Mostly sunny, with a high near 84. Breezy.
Sunday Night
Partly cloudy, with a low around 68. Breezy.
Monday
A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 88. Breezy.
Monday Night
Showers and thunderstorms likely. Mostly cloudy, with a low around 68. Breezy.
Tuesday
Showers likely and possibly a thunderstorm. Partly sunny, with a high near 81. Breezy.
Tuesday Night
Showers likely. Mostly cloudy, with a low around 60.
Wednesday
Partly sunny, with a high near 75.
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ABOUT THIS FORECAST

 
Point Forecast:
Niantic IL
 39.85°N 89.17°W (Elev. 600 ft)
Last Update:
12:16 am CDT May 14, 2026
Forecast Valid:
12am CDT May 14, 2026-6pm CDT May 20, 2026
 
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