Incredible late September heat wave began with very little rainfall September 4-27, 1891. 1891 still ranks as one of the hottest Septembers on record with lots of dry weather. However, much of the summer saw ample rainfall & was not overly hot. The hottest weather of the summer began to arrive in late August & this heat wave was an extension of that.
From September 16-27, temperatures soared into the 90s (to even 100) in the viewing area. West Lafayette saw the 12 days of 90s with a peak of 96 on September 26.
Record high temperatures still stand to this day in 2018 for 93 set on the 17th in 1891 (only 1906 comes close with 92), 93 in 1891 set on the 18th (only 1955 comes close with 92), 94 set in 1891 for the 19th (only 1908 comes close with 93). Other still-standing record highs include 95 set on September 23, 1891 (only 1980 comes close with 91), 95 on the 24th (only 1908 comes close with 92), 94 on the 25th (only 1908 comes close with 91), 96 on the 26th (only 1998 comes close with 91) & 93 set on September 27 (only 1998 comes close with 1992).
The 96 on September 26, 1891 was the latest such reading on record until 96 was reached in the heat wave on September 30, 1953.
Note the lack of rainfall over the eastern U.S. in September of 1891. Many locations saw amounts of less than 1". Only Florida, parts of the Gulf Coast, pockets of the Mid-Atlantic & a swath from Kansas to west Texas saw above normal rainfall. A corridor from central & northern Indiana to Wisconsin was especially dry with multiple locations seeing 0.30" or less. Temperatures were well-above normal over much of this part of the country.
Really healthy rains did not fall in our viewing area until November 8-10, 1891. Purdue University measured 2.74" 8-10th.
Extensive wildfires were reported over the Dakotas & Wisconsin by late month, as well as in the Ozarks of Arkansas.