IOWA PRELIMINARY WEATHER SUMMARYWritten by Theresa Rose on July 17, 2017
By Harry Hillaker, State Climatologist, Iowa Department of Agriculture & Land Stewardship
It was another week of mostly warmer than normal weather with highly variable rain totals. Hot and humid weather predominated from Sunday (9th) through Wednesday (12th) and again over the following weekend. Humidity and temperatures were somewhat lower on Thursday (13th) and Friday (14th). Temperature extremes varied from a Monday (10th) afternoon high of 98 degrees at Ottumwa (the highest official temperature thus far this summer in Iowa) to Friday (14th) morning lows of 49 degrees at Estherville and Swea City. Temperatures for the week as a whole averaged from one to two degrees below normal across the northeast one-third or so of Iowa to three to five degrees above normal over the southwest one-third with a statewide average of 1.5 degrees above normal. Just about all of the week’s rain fell between early Monday (10th) morning and Thursday (13th) morning. Thunderstorms brought rain to about the northeast one-half of the state Monday (10th) morning with totals of one to two inches common along, and just east of, a Mason City-Iowa City-Burlington line. Thunderstorms brought scattered rainfall from west central, through central, to southeast Iowa on Tuesday (11th) morning with a few small areas seeing more than an inch of rain. A small area of thunderstorms developed across extreme northeast Iowa late Tuesday night into Wednesday morning with 6.35 inches of rain recorded at Garber with still greater unofficial amounts reported in far southeastern Clayton County resulting in significant flash flooding. Finally, rain fell over most of the southeast two-thirds of Iowa on Wednesday (12th) into Thursday (13th) morning with some locally heavy rains in far southwest and extreme southeast Iowa. Weekly rain totals varied from only sprinkles in extreme northwest Iowa to 7.03 inches at Garber. The statewide average rainfall was 0.86 inches while normal for the week is 1.05 inches. Rock Rapids has recorded only 0.01 inch of rain thus far in July while Keosauqua at the opposite end of the state has recorded only 3.50 inches of rain since May 11, 7.03 inches less than normal for the period.