The day count for meteorological summer ran out over the reporting period as cooler temperatures filtered into the state towards the weekend. Weekly temperatures were still unseasonably warm with positive departures of up to four degrees; the statewide average temperature was 71.4 degrees, 1.4 degrees above normal. Rainfall was also below average statewide with departures approaching 0.80 inch. Only a handful of stations in eastern Iowa measured above-average totals.
Showers and thunderstorms continued to push out of eastern Iowa through Sunday (28th) afternoon as clouds cleared across western Iowa. Lower 80s were reported in eastern Iowa, where the sun was shielded behind cumulus clouds, while upper 80s were found farther west. A secondary cold front moved through Iowa overnight, producing spotty thunderstorms in western and central Iowa just before sunrise. Rain totals reported at 7:00 am on Monday (29th) were highest in northeastern and east-central Iowa, with more and 0.50 inch measured at 20 stations; Calamus (Clinton County) reported 1.13 inches while Cresco (Winneshiek County) observed 1.40 inch. A narrow line of severe-warned thunderstorms continued through central and southern Iowa through the late morning hours before crossing the Iowa-Illinois border before noon. Accumulating rains were isolated to Iowa's southeastern one-quarter with Chariton (Lucas County) picking up 0.22 inch and a 0.64 inch-total found in Muscatine (Muscatine County). Winds shifted to the northwest behind the front with seasonal high temperatures in the low 80s under clear skies. Starry skies persisted into Tuesday (30th) morning as calm conditions allowed temperatures to drop in the upper 40s and low 50s in western Iowa; upper 50s and low 60s blanketed eastern Iowa as the sun rose. Daytime highs were very pleasant, reaching into the mid 70s east to low 80s west under a nice northerly breeze and cloudless skies. Winds shifted to an easterly direction as darkness overtook Iowa into Wednesday (31st) with morning lows in the 50s statewide. Afternoon temperatures were warmer than the previous days as southerly winds helped boost readings into the upper 80s and low 90s south and west with mid to upper 80s northeast. A few spotty thundershowers held together over the South Dakota border into the evening hours before dissipating.
Partly cloudy skies developed into early Thursday (1st) as a disturbance approached western Iowa. Afternoon conditions varied from upper 80s and low 90s northwest to upper 70s to mid 80s south, where clouds tamped down on daytime heating as showers developed. This cluster of rainfall expanded into central Iowa through the evening hours as a few thundershowers also fired. Rainfall dissipated in northeast Iowa through the later morning hours on Friday (2nd) as clearing skies greeted most of Iowa's reporting stations. Morning lows remained in 60s with generally light rainfall totals observed along a narrow swath; a handful of stations reported over 0.30 inch with Garwin (Tama County) registering 0.33 inch and Norwalk (Warren County) dumping out 1.02 inches. Southerly winds built back in through the day as a cold front dropped southeast, pushing temperatures in the low 90s over much of Iowa. Temperatures behind the front remained in the lower 80s. A few isolated, near-stationary thunderstorms popped in southern Iowa through the evening hours along with more scattered cells along the frontal boundary into nighttime. Cooler air flowed in behind the cold front as winds shifted to the north; 50s were observed in western Iowa with mid 60s still hanging on in the east. Saturday (3rd) was a seasonal day in Iowa with daytime temperatures in the upper 70s and low 80s under brilliant sunshine. Chilly overnight lows greeted sunrise on Sunday (4th) with upper 40s and low 50s statewide.
Weekly precipitation totals ranged from no accumulation at several northwestern Iowa stations to 1.80 inches at the National Weather Service office in Davenport (Scott County). The statewide weekly average precipitation was 0.25 inch while the normal is 0.90 inch. Donnellson (Lee County) and Osceola (Clarke County) reported the week's high temperature of 95 degrees on the 29th and 2nd, respectively, on average 12 degrees above normal. Airports in Spencer (Clay County) and Sioux City (Woodbury County) reported the week's low temperature of 47 degrees on the 4th, on average eight degrees below normal.
Categories: Iowa, Weather