Weekly Iowa Weather Conditions Report, May 21, 2017

The reporting week began with dry and very warm weather on Sunday with afternoon highs in the eighties statewide. However, the remainder of the week brought frequent rain and several episodes of severe weather.

Monday and Monday night brought thunderstorms to about the north one-third of the state. Rainfall amounts with these storms were mostly under one-half inch, however, severe weather in the form of hail and high winds were reported from 20 counties Monday evening into early Tuesday morning.

Monday was very warm and humid with temperatures reaching 94 degrees at Shenandoah. Temperatures again climbed into the eighties statewide on Tuesday with thunderstorms erupting over about the northwest one-half of Iowa on Tuesday evening and night. Rainfall amounts of one to two inches were common with these Tuesday storms with high winds and large hail reported from 24 counties centered from west central across to north central Iowa.

Wednesday was the most active weather day of the week with thunderstorms statewide. Severe weather, mostly high winds, were reported from 55 counties Wednesday evening, mostly across the east two-thirds of the state. Much cooler weather prevailed for the second one-half of the week. Thursday was dry during the daylight hours with high temperatures in the mid-fifties northwest to mid-seventies southeast. However, showers and thunderstorms brought statewide rain from Thursday night through Saturday. Daytime highs were only in the forties and fifties on Friday. Sunday was mostly dry with highs in the upper forties northeast to mid-sixties southwest.

Weekly rain totals varied from 0.76 inches near New London in Henry County to 5.78 inches near Mondamin in Harrison County. The statewide average precipitation was 2.56 inches or nearly two and one-half times the weekly normal of 1.05 inches. This was the highest weekly average in the state since the third week of August in 2015.

Very warm weather early in the week was basically cancelled out with much colder weather during the second one-half of the week with a statewide average temperature of 0.2 degrees above normal. The week’s lowest temperatures were 36 degree readings at Sibley, Sioux Center and Sheldon on Sunday morning.

Source:  Harry Hillaker, State Climatologist, Iowa Department of Agriculture & Land Stewardship