Temperatures are expected to soar into the 90s on Saturday, with the heat index reaching 100-105 degrees on Saturday, Sunday and Monday. A National Weather Service Extreme Heat Warning is scheduled to go into effect for Cook County at 10 a.m. and expire at 12 a.m. Tuesday.

Chicago’s average high for this time of year is about 82 degrees, but forecasts show highs of 94 to 98 degrees over the weekend. Low temperatures will remain well above normal too, offering little relief overnight.