National Weather Service Forecast for: Plainfield IL
Issued by: National Weather Service Chicago, IL
Updated: 2:41 am CDT Jun 30, 2026
 
Overnight

Overnight: Mostly clear, with a low around 77. South southwest wind around 10 mph, with gusts as high as 15 mph.
Mostly Clear

 Tuesday

Tuesday: Mostly sunny, with a high near 93. Heat index values as high as 108. Southwest wind 10 to 15 mph, with gusts as high as 30 mph.
Mostly Sunny

 Tuesday
Night
Tuesday Night: Mostly clear, with a low around 76. Southwest wind 10 to 15 mph, with gusts as high as 30 mph.
Mostly Clear

 Wednesday

Wednesday: Sunny, with a high near 94. Heat index values as high as 107. Southwest wind 10 to 15 mph, with gusts as high as 25 mph.
Sunny

 Wednesday
Night
Wednesday Night: Mostly clear, with a low around 76. South southwest wind 10 to 15 mph, with gusts as high as 25 mph.
Mostly Clear

 Thursday

Thursday: Sunny, with a high near 93.
Sunny

 Thursday
Night
Thursday Night: A 50 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 74.
Slight Chance
T-storms then
Chance
T-storms
 Friday

Friday: Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91.
Showers
Likely

 Friday
Night
Friday Night: A chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 72.
Chance
T-storms
Lo 77 °F Hi 93 °F Lo 76 °F Hi 94 °F Lo 76 °F Hi 93 °F Lo 74 °F Hi 91 °F Lo 72 °F

Hazardous Weather Outlook
Extreme Heat Warning
 

Overnight
 
 Mostly clear, with a low around 77. South southwest wind around 10 mph, with gusts as high as 15 mph.
Tuesday
 
 Mostly sunny, with a high near 93. Heat index values as high as 108. Southwest wind 10 to 15 mph, with gusts as high as 30 mph.
Tuesday Night
 
 Mostly clear, with a low around 76. Southwest wind 10 to 15 mph, with gusts as high as 30 mph.
Wednesday
 
 Sunny, with a high near 94. Heat index values as high as 107. Southwest wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday Night
 
 Mostly clear, with a low around 76. South southwest wind 10 to 15 mph, with gusts as high as 25 mph.
Thursday
 
 Sunny, with a high near 93.
Thursday Night
 
 A 50 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 74.
Friday
 
 Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91.
Friday Night
 
 A chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 72.
Independence Day
 
 A chance of showers and thunderstorms. Mostly sunny, with a high near 89.
Saturday Night
 
 A chance of showers and thunderstorms. Mostly cloudy, with a low around 69.
Sunday
 
 A chance of showers and thunderstorms. Partly sunny, with a high near 87.
Sunday Night
 
 Partly cloudy, with a low around 67.
Monday
 
 Mostly sunny, with a high near 86.

 

Forecast from NOAA-NWS for Plainfield IL.