Prior to 1950, temperatures over 40C were much more common in Wisconsin, but they almost never happen any more. In 1936, more than one percent of all maximum temperatures recorded were over 40C.
President Obama says that heatwaves are getting hotter and longer in the US.
Fewer severe heatwaves are entirely consistent with a warming climate (sarc). I should not have to use the sarc label, but that is the actual bullcrap that alarmists are trying to shove down people’s throats.