Chicago just hit the magical 38.3°C (100°F) that we have avoided for over 11 years, and with the 25.6°C dewpoint it feels like 48.1°C (118.6°F):
Here at IDTWHQ it got 0.2°C warmer than yesterday but it seems to have peaked:
Our little weather station also has a similar dewpoint, giving us a heat index just a scoche lower at 44°C (111°F). It turns out, the Midwest has some really uncomfortable dewpoints right now because we raise crops nearby. Evapotranspiration from the thousands of hectares of soybean and feed corn crops near Chicago increases the moisture in the atmosphere to uncomfortable levels every August. The annual cicadas love it; I don't.
You may also notice that it didn't really cool off last night. Cassie and I went for our long walk of the day at 6:45am, right in the middle of that trough when it felt like swimming through the Persian Gulf (temperature 28.3°C dewpoint 25°C, heat index 33.3°C/92.0°F). Cassie spent the next hour next to the AC vent in the coolest room in the house while I took a shower.
Nevertheless, a cold front continues to ease in from the north, and should pass over Chicago between 7pm and 11pm, dropping the temperature down to 22°C by midnight and keeping it under 24°C tomorrow. At least, by the Lake. I plan to visit a couple of breweries in Lake County where it might get up to 27°C.
But I might open the windows Saturday as the blocking high behind the cold front moves over Chicago and gives us even cooler temperatures—and lower dewpoints. And let's not forget: autumn officially starts a week from tomorrow.