9/29/26 - Maybe the Wettest September on Record

[00:00:31] Iowa weather history: a look back at late-September 1985, when widespread rain, sleet, and snow occurred across Iowa, including trace snowfall in Des Moines.

[00:01:26] Forecast headline: widespread rainfall continues through Thursday night, fueled by tropical moisture associated with Hurricane Polo's remnants, monsoonal moisture, and a larger-scale low-pressure system.

[00:02:00] Pattern change ahead: sunshine, daytime temperatures in the 60s, overnight lows in the 40s, and a drier, less active weather pattern beginning Friday.

[00:02:24] September rainfall records: Des Moines may approach or break its wettest September on record, while only 2.76 inches are needed to break the city's all-time wettest-month record.

[00:03:47] Statewide September climate update: Iowa ranks as the fifth warmest and seventh wettest September in 154 years of records, with some locations receiving May-and-June-scale precipitation totals in one month.

[00:04:51] Extended outlook: the 8-to-14-day and 3-to-4-week forecasts favor a generally drier pattern. Keep an eye on a short-lived period of much-below-normal temperatures 10/6-10/7 in SE Iowa.

[00:07:41] Past-week weather recap: temperatures were slightly below normal for the first time this September, while statewide rainfall averaged 1.26 inches.

[00:08:36] Weekly extremes: Clarinda and Shenandoah reached 80°F; Hampton dropped to 45°F; Missouri Valley received 2.73 inches of rain; and parts along the Iowa-Wisconsin border received little or no rain.

[00:09:20] Specialty-crop update: sweet potatoes are thriving in the warm, wet season, but harvest appropriately sized roots before they become oversized and harder to market.

[00:10:38] Cloud cover and crop growth: Dan and Justin discuss whether unusually cloudy conditions may be limiting photosynthesis, crop sizing, and fall growth; they plan to revisit cloud-cover data next week.

[00:11:42] Fall foliage and warm nights: persistent greenness and delayed leaf-color change may reflect warm overnight temperatures and the broader warming signal associated with climate change.

[00:12:25] Recommended listening: Dan highlights a recent weather-focused episode of the Growing for Market podcast featuring a Northeast meteorologist.