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

Excessive Rainfall and Significant Flooding in the Upper Midwest This Weekend

Heavy to excessive rainfall is expected over the weekend across eastern Iowa, northern Missouri, northwest Illinois and southern Wisconsin. Numerous flash floods, some with significant impacts, are expected in these areas. Heaviest rainfall will occur overnight Saturday and Sunday, so be sure to have multiple ways to receive warnings. Read More >

Hazardous Weather Conditions

Current conditions at

Gary Regional Airport (KGYY)

Lat: 41.61°NLon: 87.41°WElev: 584ft.

Fair

90°F

32°C

Humidity 63%
Wind Speed SE 7 G 22 mph
Barometer 30.06 in
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index101°F (38°C)
Last update 9 Aug 10:45 am CDT
Extended Forecast for

Merrillville IN

  • Today

    Today: Sunny, with a high near 91. Heat index values as high as 97. South wind around 15 mph, with gusts as high as 20 mph.

    High: 91 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 72. South wind 5 to 10 mph, with gusts as high as 15 mph.

    Low: 72 °F

    Mostly Clear

  • Sunday

    Sunday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 89. Heat index values as high as 95. South southwest wind 5 to 10 mph, with gusts as high as 15 mph.

    High: 89 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Sunday Night

    Sunday Night: A 30 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 71. South wind around 5 mph, with gusts as high as 10 mph.

    Low: 71 °F

    Partly Cloudy
    then Chance
    Showers

  • Monday

    Monday: A 50 percent chance of showers and thunderstorms. Mostly sunny, with a high near 88. South southwest wind 5 to 10 mph, with gusts as high as 15 mph.

    High: 88 °F

    Chance
    Showers then
    Chance
    T-storms

  • Monday Night

    Monday Night: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 69.

    Low: 69 °F

    Chance
    T-storms

  • Tuesday

    Tuesday: A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 86.

    High: 86 °F

    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 68.

    Low: 68 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86.

    High: 86 °F

    Mostly Sunny
    then Chance
    T-storms

Detailed Forecast

Today
Sunny, with a high near 91. Heat index values as high as 97. South wind around 15 mph, with gusts as high as 20 mph.
Tonight
Mostly clear, with a low around 72. South wind 5 to 10 mph, with gusts as high as 15 mph.
Sunday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 89. Heat index values as high as 95. South southwest wind 5 to 10 mph, with gusts as high as 15 mph.
Sunday Night
A 30 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 71. South wind around 5 mph, with gusts as high as 10 mph.
Monday
A 50 percent chance of showers and thunderstorms. Mostly sunny, with a high near 88. South southwest wind 5 to 10 mph, with gusts as high as 15 mph.
Monday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 69.
Tuesday
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 86.
Tuesday Night
Mostly cloudy, with a low around 68.
Wednesday
A chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 86.
Wednesday Night
Partly cloudy, with a low around 68.
Thursday
A chance of showers. Mostly sunny, with a high near 87.
Thursday Night
Partly cloudy, with a low around 69.
Friday
Mostly sunny, with a high near 88.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Merrillville IN
 41.47°N 87.33°W
Last Update:
10:06 am CDT Aug 9, 2025
Forecast Valid:
11am CDT Aug 9, 2025-6pm CDT Aug 15, 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