Weather Summary

Provided by Justin Glisan, Ph.D., State Climatologist, Iowa Department of Agriculture and Land Stewardship

Iowans experienced ideal conditions for field work and planting during much of the reporting period. A late-week active storm track brought widespread rainfall along with severe thunderstorms. Even with widespread wetness, unseasonably dry conditions persisted. Temperatures were more variable than the previous week with warmer conditions north to cooler readings south; in between, near-normal behavior with the statewide average temperature coming in at 56.0 degrees, 0.1 degree above normal. A cut-off low pressure center over the Great Lakes dominated the weather pattern as it spun showers into eastern Iowa through Sunday (30th) afternoon. Daytime highs varied from the mid-40s east, where clouds and rain were present, to the upper 50s west under clearing skies. Very strong northwesterly winds built in through the day with sustained speeds in the 30-40 mph range and gusts above 50 mph; Spencer Municipal Airport (Clay County) observed a 59-mph wind gust. Clouds quickly diminished overnight with Monday (1st) morning lows in the upper 30s and low 40s. After a brief lull in stronger winds, speeds increased through the afternoon hours with upper 50s and low 60s reported under sunny skies. A band of clouds moved north to south across Iowa into early Tuesday (2nd) morning, though starry skies were visible for most of the night. Strong northwesterly winds persisted with pleasant temperatures in the low to mid-60s. Winds finally died down before sunset on Wednesday (3rd) with morning lows in the low 30s north to upper 30s south under cloudless skies. Daytime highs pushed into the upper 60s and low 70s with light and variable winds and clear skies. Temperatures on Thursday (4th) afternoon were several degrees warmer, hitting the low 80s at multiple stations after morning temperatures bottomed out in the 40s with winds shifting to the south under clear conditions.

Spotty thundershowers formed in extreme northwest Iowa later in the night with a more widespread shield of rainfall forming Friday (5th) morning. The sluggish disturbance moved across central and eastern Iowa where temperatures held in the low to mid-60s. A second band of stronger storms pushed through northern Iowa prior to sunrise on Saturday (6th) before fizzling out around noon. Rain totals were highest in west-central Iowa where several stations measured at least an inch with widespread 0.25 – 0.50 inch totals over Iowa’s middle west-to-east one-third; the statewide average rainfall was 0.40 inch. Southerly winds boosted daytime temperatures into the upper 70s and low 80s over southern Iowa where southerly winds brought in higher dewpoints. A few severe-warned cells fired in southwest Iowa before diving across the Missouri border. Additional severe thunderstorms formed several hours later and overnight into Sunday (7th) in southeastern Iowa. These storms brought locally heavy downpours along with hail and straight-line wind reports across Van Buren, Henry and Lee counties. Many stations in southeastern counties also measured totals from 0.40 inch at Columbus Junction (Louisa County) to 1.17 inches in Augusta (Lee County). Heavy dew and dense fog were observed at 7:00 am over much of the state with cloudy skies and lows in the upper 50s to mid-60s.

Weekly precipitation totals ranged from no accumulation at several Iowa stations to 1.76 inches at Redfield (Dallas County). The statewide weekly average precipitation was 0.50 inch while the normal is 0.89 inch. Little Sioux (Harrison County) and Sioux City Municipal Airport (Woodbury County) reported the week’s high temperature of 86 degrees on the 4th, on average 18 degrees above normal. Chariton (Lucas County) and Vinton (Benton County) reported the week’s low temperature of 25 degrees on the 3rd, on average 16 degrees below normal. Four-inch soil temperatures were in the upper 50s north to mid-60s south as of Sunday.