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
Warmer than normal temperatures are expected through the week, about 5 degrees above normal. Average highs for late August range from the upper 70s in northern Iowa to the low 80s in southern Iowa.
Precipitation
It's been a quiet several days and will continue to be mild the next few days. Chances for rain return on Saturday, and slight chances for rain continue through early next week. Seven-day rainfall totals remain low for the state, with greatest amounts forecast for northern Iowa. Refer to local point forecasts from the National Weather Service for the most up to date information on your forecast.
Trivia Question - Madelynn Wuestenberg
What causes the moon to look red during a lunar eclipse?
Climate Outlook - Madelynn Wuestenberg
8-14 Day Outlook (September 3-9)
Temperature
Warm conditions are expected to continue for the next couple of weeks. Iowa has increased chances for above-normal temperatures. Most of the state has a 50-60% chance of above-normal temperatures, and the very northwestern corner has a 40-50% chance of above-normal temperatures.
Precipitation
Iowa continues to have near-normal chances for precipitation. 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.
September Outlook
The September outlook was issued on August 20th and is valid for the month of September.
Temperature
There is limited guidance in the September temperature outlook with equal chances for above-, below-, or near-normal temperatures across the state of Iowa.
Precipitation
Southern Iowa has a slightly increased chance for precipitation during September, but the rest of the state lies in equal chances.
Seasonal Outlook
The seasonal outlook was issued on August 20th and is valid for the months of September, October, and November.
Temperature
There is a slightly increased chance, 33-40%, for above normal temperatures in Iowa.
Precipitation
For Iowa, there are equal chances for above, below, or near-normal precipitation totals for the seasonal outlook. There is an increased chance of precipitation in the desert Southwest, which is a common pattern to see with very strong El Niño conditions.
Past Week of Weather - Madelynn Wuestenberg
Temperature
Conditions have been very pleasant across the state for the past week.
- Hottest Place: Rock Rapids, 90 degrees F on August 26.
- Coldest Place: Spencer Municipal Airport and Lake Park, 47 degrees F on August 23.
Precipitation
Dry conditions for most of the state, with many stations recording no measurable precipitation.
- Wettest Place: Boone, 0.63 inches.
- Driest Place: Many stations across north-central through eastern Iowa, no precipitation.
Other Notable Weather
The Iowa State Fair had record attendance, likely in part thanks to beautiful weather conditions. Temperatures were favorable and there were dry conditions in Des Moines during the second half of last week.
A deep partial lunar eclipse will occur tonight, August 27, with peak viewing in the central time zone at 11:12 PM. At maximum eclipse, 96.3% of the Moon will be covered, according to NASA. The next full lunar eclipse will occur June 25, 2029.
Come visit the What in the Weather team at the Farm Progress Show in Boone next week! We will be recording live from the show on Wednesday.
Trivia Answer: Rayleigh scattering
What causes the moon to look red during a lunar eclipse? Rayleigh scattering! Atmospheric constituent gases scatter incoming solar radiation, and radiation of different wavelengths scatter more or less. Blue has a short wavelength and is scattered more than red, which is why the sky appears blue during the day and why sunsets are red.
This day in Iowa Weather History - Dr. Justin Glisan
"Back in 1903, slow-moving thunderstorms dropped tremendous amounts of rain across portions of southern Iowa from the evening of August 26th through the morning of the 27th. The heaviest rain fell across Clarke, Lucas, and Decatur counties, where rainfall amounts in less than 24 hours included 9.34 inches in Osceola, 10.08 inches at Hopeville, 11.22 inches at Sheridan, and 14.61 inches at Woodburn. Now I have to check this. This is hot off the press because that’s higher than the Atlantic 13.18 inches, which is the 24-hour record, so it looks like this rainfall amount is unofficial."
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 27, 2026. The information contained within may not be the most current and accurate depending on when it is accessed.
- Weather and Climate Extension Specialist