When Will We Feel 100-Degree Heat? Hour-by-Hour Forecast

Today will be a hot one and get hotter as the day goes on. We'll reach a peak heat index of 100 degrees around 4 p.m., according to the National Weather Service.

Time, Temperature and Heat Index

• 8 am: 80°, 80°
• 10 am: 85°, 91°
• 1 pm: 92°, 99°
• Peak Heat at 4 pm: 93°, 100°
• 7 pm: 88°, 95°
• 10 pm: 82°, 87°

Friday will follow the same pattern, starting off at 78 degrees at 7 a.m., but the NWS doesn't expect the day to be as hot, topping out with a temperature of 88 degrees and heat index of 97 at 4 p.m.

Then we begin a cool down, with highs in the mid-80s come Saturday.

check the Chicago-area weather forecast details »