National Weather Service

News Headlines

August 9, 2026: Two Rounds of Severe Thunderstorms, Including Late Night Tornadoes in North-Central Illinois
August 11, 2026: Powerful Morning Derecho Produces Widespread Wind Damage and Tornadoes Across Northern Illinois and Northwest Indiana

Hazardous Weather Conditions

Current conditions at

Chicago/Waukegan Regional Airport (KUGN)

Lat: 42.43°NLon: 87.86°WElev: 709ft.

A Few Clouds

77°F

25°C

Humidity	66%
Wind Speed	SW 10 mph
Barometer	29.94 in (1013.0 mb)
Dewpoint	65°F (18°C)
Visibility	10.00 mi
Heat Index	79°F (26°C)
Last update	21 Aug 4:51 pm CDT

More Information:

Local Forecast Office More Local Wx 3 Day History Hourly Weather Forecast

Extended Forecast for

Round Lake IL

Severe T-storm Watch until August 21, 10:00pm

Click here for hazard details and duration

Severe T-storm Watch

Severe T-storm Watch until August 21, 10:00pm
NOW until 10:00pm Fri
Severe T-storm Watch
This Afternoon
High: 78 °F
Severe
Thunderstorms
Tonight
Low: 61 °F
Severe
Thunderstorms
then Partly
Cloudy
Saturday
High: 78 °F
Mostly Sunny
then Slight
Chance
T-storms
Saturday Night
Low: 56 °F
Mostly Clear
Sunday
High: 75 °F
Sunny
Sunday Night
Low: 55 °F
Mostly Clear
Monday
High: 76 °F
Mostly Sunny
Monday Night
Low: 58 °F
Partly Cloudy

Detailed Forecast

This Afternoon

Showers and thunderstorms likely. Some of the storms could be severe. Mostly cloudy, with a high near 78. South southwest wind around 10 mph, with gusts as high as 15 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Tonight

Showers and thunderstorms likely, mainly before 11pm. Some of the storms could be severe. Mostly cloudy, with a low around 61. South southwest wind around 5 mph becoming west northwest after midnight. Winds could gust as high as 15 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Saturday

A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 78. Northwest wind 5 to 15 mph, with gusts as high as 25 mph.

Saturday Night

Mostly clear, with a low around 56. North northwest wind 5 to 10 mph, with gusts as high as 15 mph.

Sunday

Sunny, with a high near 75. Northwest wind 5 to 10 mph, with gusts as high as 15 mph.

Sunday Night

Mostly clear, with a low around 55.

Monday

Mostly sunny, with a high near 76.

Monday Night

Partly cloudy, with a low around 58.

Tuesday

Mostly sunny, with a high near 79.