The following content is summarized from the What in the Weather Podcast by Dan Fillius, Justin Glisan, and Madelynn Wuestenberg.
You can find more information about weather impacts on specialty crops and home horticulture on Dan Fillius' website and information from today's podcast on the latest newsletter.
7-day Weather Forecast - Dr. Justin Glisan
Temperature
Another week of seasonal temperatures are expected through the week. Highs will range from the upper 70s in northern Iowa to the lower 80s in southern Iowa. Overnight lows are generally forecasted to be in the 60s across the state.
Precipitation
Storms are expected (and occurring as this is written) in southwestern and southern Iowa. Locally heavy rainfall is possible. Additional thunderstorms are expected in the state on Thursday night into Friday and into Friday night. Patchy fog is possible. The weekend is expected to be quieter for much of the state. 7-day rainfall totals are expected to be generally under a half inch for the state. Refer to local point forecasts from the National Weather Service for the most up to date information on your forecast.
Trivia Question - Madelynn Wuestenberg
True or False: It is safe to park under an overpass while driving through a storm.
Climate Outlook - Madelynn Wuestenberg
8-14 Day Outlook (August 26 - September 1)
Temperature
Iowa has increased chances for above-normal temperatures. The eastern portion of the state has a 33 to 40% chance of above-normal temperatures, while western Iowa has a 40 to 50% chance for above-normal temperatures.
Precipitation
Iowa has near-normal chances for precipitation. Near-normal precipitation does not mean no rainfall; normal precipitation for this time of year is roughly one-half inch to three-quarters of an inch per week. Climatologically, weekly precipitation totals are beginning to taper as we get closer to fall.
3-4 Week Outlook (August 29 - September 11)
Temperature
Equal chances for above-, below-, or near-normal in most of Iowa, with a small sliver of slight (33-40%) chance for above normal temperatures in the very southwest corner of Iowa.
Precipitation
Equal chances for above-, below-, or near-normal precipitation in most of Iowa, with an area of slight (33-40%) chance of below normal precipitation in northeastern Iowa.
Past Week of Weather - Madelynn Wuestenberg
Temperature
Overall, temperatures have been warm for the past week. Overnight temperatures were above average.
- Hottest Place: Donaldson, 94 degrees F on August 15.
- Coldest Place: Mapleton, 51 degrees F on August 13.
Precipitation
Storms at the end of last week brought plenty of rain across the state. Heaviest totals fell in a band across the central part of the state. Several locations across the state reported strong winds with these storms.
- Wettest Place: Wapello in Louisa County, 8.76 inches.
- Driest Place: Rock Rapids in Lyon County, 0.13 inches.
Other Notable Weather
Iowa experienced its wettest week of the year, on average across the state, for year-to-date when measured from Monday through Sunday. The statewide average precipitation for the past week was 2.6 inches above the climatological average for this reporting period.
The Climate Prediction Center forecasts for El Niño continue to show high chances for a strong El Niño this fall into winter. Forecasts show a 93% chance for September through November, 95% chance for October through December, and a 90% chance for November through January.
Trivia Answer: False, do not park under an overpass during a storm
It is unsafe to park under an overpass, especially if there is a tornado. Low visibility, stopped vehicles, and limited room to pass can create conditions for crashes. It is best to exit off the interstate during times of low visibility and stop the car or find the nearest rest stop.
This day in Iowa Weather History - Dr. Justin Glisan
“On August 19, 1898, thunderstorms produced severe straight-line winds, locally heavy rain, and hail across the northwestern third of Iowa during the late afternoon and evening. The damage swath was about 10 miles wide and 15 to 20 miles long. From Spencer to Emmetsburg, strong winds and very large hail cut all crops to the ground. Near Spirit Lake, severe winds caused widespread, significant damage to buildings, trees, and utility poles. Freight cars were blown over, and numerous barns and outbuildings were completely destroyed. A couple was killed near Peterson in Clay County when the barn in which they were sheltering was blown to pieces. A man was also killed by a lightning strike near Boone.”
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on August 19, 2026. The information contained within may not be the most current and accurate depending on when it is accessed.
- Weather and Climate Extension Specialist