From NWS
1988: In the midst of a significant drought a large and strong dust devil developed on the edge of Lake Okoboji in Dickinson County, picking up sections of docks and “sweeping away all of the loose dirt in the area” with winds estimated at 60 mph or higher.

1901: Extremely hot weather smothered Iowa for much of July with the longest and most intense period of heat settling in from the 9th-26th. The heat was so persistent that nine stations reached or exceeded 100 F on all 18 of those days, including Ames, Clarinda, Council Bluffs, and Sigourney. At Logan the 100 F mark was reached on a staggering 20 consecutive days from the 8th-27th, with lows in the 70s on 14 of those days and a low temperature of 67 F for the entire 20-day stretch. At Ottumwa the low temperature from the 9th-26th was 70 F and on four of those days lows were in the lower 80s. The highest temperature recorded in Iowa during this remarkable heat wave was 113 F at Sigourney on the 22nd, a day on which only three reporting stations in the state failed to reach 100 F and other high temperatures included 112 F at Bonaparte, 111 F at Harlan, and 110 F at Albia, Keosauqua, Pella, and Primghar. The month of July, 1901 was unmatched for heat in Iowa weather records until finally bested during the Dust Bowl summers of 1934 and 1936.

22 July 1918 → A single bolt of lightning struck 504 sheep dead in their tracks at the Wasatch National Forest in Utah. Sheep often herd together in storms, and as a result the shock from the lightning bolt was passed from one animal to another.

Posted under Weather History