The heat warning will take effect at 7 a.m. Wednesday and will continue through 4 p.m. Friday.
The National Weather Service has issued an excessive heat warning for McHenry County as temperatures coupled with the humidity are expected to make for some very uncomfortable weather. The excessive heat warning in McHenry County will take effect at 7 a.m. Wednesday and will continue through 4 a.m. Friday, according to the National Weather Service. Oppressive humidity and temperatures reaching into the upper 90s Wednesday and Thursday could result in dangerously high heat indexes during the afternoon hours, according to the NWS. Nighttime could offer little relief. Lows are expected to be in the mid-to-upper 70s Wednesday, according to the NWS. The NWS offers the following tips on how to stay safe in the extreme heat: