Iowa Weekly Growing Season Report

Preliminary weather summary for the week ending May 22, 2022

Temperatures moderated across Iowa through the reporting period with slightly warmer than average conditions over portions of the state. Average temperatures were up to three degrees above normal in west-central Iowa, though near-normal or colder than average conditions were reported at stations around the periphery; the statewide average temperature was 61.7 degrees, 1.6 degrees below normal. Rainfall was widespread but below-average statewide with departures of up to an inch at several stations.

Showers dissipated across central and eastern Iowa into Sunday (15th) evening with winds shifting northwesterly and skies gradually clearing. Daytime highs reached into to the mid 70s north while thicker clouds held temperatures in the 60s south. Rain totals reported at 7:00 am on Monday (16th) were generally at or below 0.10 inch with four stations in Appanoose and Davis counties measuring from 0.33 to 0.41 inch. Afternoon temperatures hovered in the upper 70s and low 80s under partly to mostly sunny skies. Clouds streamed into northern Iowa overnight as light showers formed ahead of a low pressure center transiting through Nebraska. The disturbance slowly moved through Iowa on Tuesday (17th) with stronger thunderstorms firing in the southwest where moderate rainfall was observed. Temperatures varied from the upper 50s northeast to low 80s in southeastern Iowa where the sun was shining. Most of Iowa’s stations reported measurable rainfall with 25 stations measuring an inch or more; Numa (Appanoose County) observed 1.01 inches while Logan (Harrison County) registered 2.44 inches with the statewide average coming in at 0.31 inch. Showers lingered in eastern Iowa after daybreak on Wednesday (18th) with morning lows in the low 50s north to low 60s south under cloudy skies. Clouds gradually thinned and moved out of the state through the day with highs in the upper 70s and low 80s across much of Iowa’s western two-thirds. Winds started shifting to a southerly direction as another weather system moved into the Upper Midwest; overnight temperatures stayed in the upper 50s and low 60s.

Thursday (19th) saw multiple rounds of showers and thunderstorms move through Iowa as a strong low pushed across Minnesota. Northern Iowa experienced showers and thunderstorms from late morning into the early afternoon hours with isolated, stronger storms forming later in the afternoon along the Iowa-Minnesota border. A third round of thunderstorms, some turning severe, fired along the low’s attendant cold front in the late night hours and early into Friday (20th). Gusty winds and one inch hail were reported in west-central Iowa where Denison (Crawford County) measured a 63 mph gust from a severe-warned thunderstorm. Moderate rainfall was observed across Iowa’s northern quarter with general totals in the 0.10 to 0.30 inch range; Storm Lake (Buena Vista County) measured 0.38 inch. A pocket of thundershowers persisted in eastern Iowa after sunrise, though it quickly dissipated by mid-morning. Another quick-moving severe-warned cell moved through Lee County around the same time dropping one-inch diameter hail and 0.35 inch of rain at Augusta’s station. Clouds hung around for most of the day as afternoon highs held in the upper 60s. A cold front dropped southeast across Iowa overnight into Saturday (21st) shifting winds to the northwest and lowering morning temperatures into the low 40s west. Daytime conditions were colder than average with highs in the low 50s over northern Iowa and low 60s in the southeast corner. Stars gradually emerged as clouds cleared through the early morning hours into Sunday (22nd) with chilly temperatures in the low 30s in western Iowa while mid 40s were recorded east.

Weekly precipitation totals ranged from 0.02 inch in Chariton (Lucas County) to 2.49 inches in Logan. The statewide weekly average precipitation was 0.43 inch while the normal is 0.97 inch. Little Sioux (Harrison County) reported the week’s high temperature of 94 degrees on the 19th, 20 degrees above normal. Audubon (Audubon County) and Sioux City Airport (Woodbury County) reported the week’s low temperature of 30 degrees on the 22nd, on average 21 degrees below normal. Four-inch soil temperatures were in the low 50s northeast to mid 60s southwest as of Sunday.