September 5 used to be a hot day in the US, but temperatures have plummeted since the 19th century.
On this date in 1925, Arkansas, Georgia, and Mississippi all reached 110 degrees. Illinois and Tennessee were 109 degrees. Alabama, Kentucky, and Missouri were 108 degrees. South Carolina was 107 degrees, Kansas was 106 degrees, Oklahoma was 104 degrees.
Read more at Real Climate Science