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

Tropical Storm Arthur and Heavy Rainfall in the South; Severe Weather in the Midwest

An outbreak of severe thunderstorms is expected across portions of Illinois and Indiana tonight. Intense tornadoes, swaths of damaging gusts, and hail in excess of 2 inches in diameter possible. Tropical Storm Arthur will continue to produce strong winds across coastal Upper Texas and Louisiana tonight, as well as potentially life-threatening flooding across southern Louisiana into Mississippi. Read More >

Hazardous Weather Conditions

Current conditions at

Sterling Rockfalls (KSQI)

Lat: 41.74°NLon: 89.67°WElev: 643ft.

Fair

61°F

16°C

Humidity 90%
Wind Speed W 12 mph
Barometer 29.62 in (1002.5 mb)
Dewpoint 58°F (14°C)
Visibility 10.00 mi
Last update 18 Jun 5:56 am CDT
Extended Forecast for

Lyndon IL

  • Today

    Today: Mostly sunny, with a high near 73. Northwest wind 10 to 15 mph, with gusts as high as 20 mph.

    High: 73 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 54. West wind around 5 mph.

    Low: 54 °F

    Mostly Clear

  • Juneteenth

    Juneteenth: Sunny, with a high near 79. West wind 5 to 10 mph.

    High: 79 °F

    Sunny

  • Friday Night

    Friday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 58. West wind around 5 mph.

    Low: 58 °F

    Slight Chance
    T-storms

  • Saturday

    Saturday: Mostly sunny, with a high near 81.

    High: 81 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: A 40 percent chance of showers after 1am. Mostly cloudy, with a low around 59.

    Low: 59 °F

    Partly Cloudy
    then Chance
    Showers

  • Sunday

    Sunday: Showers likely, then showers and possibly a thunderstorm after 1pm. High near 74. Chance of precipitation is 80%.

    High: 74 °F

    Showers

  • Sunday Night

    Sunday Night: A 50 percent chance of showers before 1am. Mostly cloudy, with a low around 54.

    Low: 54 °F

    Chance
    Showers

  • Monday

    Monday: Mostly sunny, with a high near 75.

    High: 75 °F

    Mostly Sunny

Detailed Forecast

Today
Mostly sunny, with a high near 73. Northwest wind 10 to 15 mph, with gusts as high as 20 mph.
Tonight
Mostly clear, with a low around 54. West wind around 5 mph.
Juneteenth
Sunny, with a high near 79. West wind 5 to 10 mph.
Friday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 58. West wind around 5 mph.
Saturday
Mostly sunny, with a high near 81.
Saturday Night
A 40 percent chance of showers after 1am. Mostly cloudy, with a low around 59.
Sunday
Showers likely, then showers and possibly a thunderstorm after 1pm. High near 74. Chance of precipitation is 80%.
Sunday Night
A 50 percent chance of showers before 1am. Mostly cloudy, with a low around 54.
Monday
Mostly sunny, with a high near 75.
Monday Night
Mostly clear, with a low around 52.
Tuesday
Sunny, with a high near 78.
Tuesday Night
Partly cloudy, with a low around 56.
Wednesday
Mostly sunny, with a high near 80.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Lyndon IL
 41.72°N 89.91°W (Elev. 600 ft)
Last Update:
4:22 am CDT Jun 18, 2026
Forecast Valid:
6am CDT Jun 18, 2026-6pm CDT Jun 24, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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