Iowa Preliminary Weather Summary

Written by Theresa Rose on July 7, 2020

 

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

Unseasonably warm and dry conditions persisted through the end of June into early July across the majority of Iowa. The warmest conditions were found in eastern Iowa with positive departures of up to six degrees. The statewide average temperature was 77.4 degrees, 4.3 degrees above normal. Measurable rain was reported across most of the state, though only extreme southeast Iowa reported above normal totals; portions of north-central Iowa reported deficits of up to an inch.

Showers and thunderstorms continued to push through Iowa into Sunday (28th) afternoon with isolated thundershowers popping up into the evening hours. Daytime highs were in the 80s across the state with a southerly wind. Clouds cleared overnight into Monday (29th) with temperatures remaining in the low to mid 70s. Rain totals reported at 7:00 am for the previous 24-hour period showed widespread rainfall between 0.10 inch to 0.25 inch. Heavier pockets of rain were reported in southeastern Iowa, where Keokuk Lock and Dam (Lee County) observed 0.81 inch. Cloud cover increased across eastern Iowa through the daytime hours with mid to upper 80s reported across much of the state. A small disturbance over northeastern Missouri spun several lines of slow moving showers and thunderstorms over southeastern Iowa just after midnight on Tuesday (30th). The system lingered for most of the day with totals ranging from 0.08 inch at Burlington Municipal Airport (Des Moines County) to 1.26 inches at Fort Madison (Lee County). High temperatures were held in the upper 70s where cloud cover was present with mid to upper 80s observed in northern and western Iowa. A line of strong thunderstorms entered western Iowa early on Wednesday (1st) bringing measurable rain across much of the state’s western one-third. A secondary, narrow band of thunderstorms popped up across southeastern Iowa ahead of the primary system, bringing locally heavy rain before dissipating. Rain totals were highest in both the southwest and southeast corners with Red Oak (Montgomery County) observing 1.60 inches while Ottumwa Industrial Airport (Wapello County) reported 2.42 inches; the statewide average rainfall was 0.21 inch.

The final days of the week were relatively hot and dry with partly cloudy conditions persisting through Thursday (2nd). Daytime highs reached into the upper 80s with some readings in the 90s. Overnight lows remained in the upper 60s and low 70s, up to 10 degrees warmer at some stations with the statewide average at 67 degrees, five degrees above normal. A few isolated thunderstorms popped up over Lee and Van Buren counties during the morning hours which led to flash flood warnings. Hot conditions continued on Friday (3rd) with highs peaking in the upper 80s and low 90s. The statewide average temperature was 89 degrees, four degrees warmer than normal. Warm temperatures persisted through Saturday (4th) with a few thundershowers firing in northern and eastern Iowa. Winds were generally light and variable with puffy cumulus clouds moving across the sky. Independence Day fireworks were enjoyed under muggy conditions as a near full moon rose. Overnight lows into Sunday (5th) varied from the upper 60s to low 70s with hazy and degraded air quality conditions reported from excess particulates in the lower atmosphere.

Weekly precipitation totals ranged from no accumulation at multiple stations in north-central Iowa to 3.37 inches at Keokuk Lock and Dam (Lee County). The statewide weekly average precipitation was 0.35 inch while the normal is 1.09 inches. Bellevue Lock and Dam (Jackson County) reported the week’s high temperature of 94 degrees on the 3rd, nine degrees above normal. Mapleton (Monona County) reported the week’s low temperature of 61 degrees on the 4th, one degree below normal.