They started their graph in the 1950s. Had they used a complete data set the trend would be opposite.
They started their Illinois graph in the 1970s.
24 Jul 1934, 1 – Chicago Tribune at Newspapers.com
During the summer of 1936, Detroit had 275 heat deaths in six days, averaging one every ten minutes.
15 Jul 1936, 15 – The Dispatch at Newspapers.com
March 2, 1975 – B-r-r-r-r: New Ice Age on way soon? | Chicago Tribune Archive
Yesterday was rather cool and today, also. I think we are going into an ice age. But the day before it was 10 degrees above normal in the morning which confirmed global warming. I don’t know what to do!
The Sahel is in drought when stronger solar wind states drive a colder AMO, via positive North Atlantic Oscillation regimes. The AMO is normally warmer during centennial solar minima:
https://media.springernature.com/m685/springer-static/image/art%3A10.1038%2Fs41598-017-13246-x/MediaObjects/41598_2017_13246_Fig2_HTML.jpg