Early Fall Chill Arrives in Midwest, Northeast – But Autumn Isn’t Here Yet
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Des Moines, Iowa - August 25, 2025 – Residents across Iowa, the Midwest, and the Northeast are experiencing unseasonably cool temperatures, offering a premature taste of fall. While the drop in temperatures may feel like a seasonal shift, the official start of autumn is still weeks away.
Temperatures in Des Moines have already dipped below 80 degrees Fahrenheit,with overnight lows reaching the 50s,according to reports from Accuweather. This cool spell is a notable departure from typical late-August weather patterns.
When Does Fall Officially Begin?
The autumnal equinox, marking the official start of fall in the Northern Hemisphere, will occur at 2:19 p.m. on September 22nd. This astronomical event happens when the sun crosses the celestial equator, according to the Farmer’s Almanac. Following the equinox, daylight hours will steadily decrease, culminating in the winter solstice.
Meteorologists often define fall as the three-month period from September through November.
Why the Early Chill?
The current cool temperatures in Iowa are attributed to a combination of factors: a southward-moving air mass originating in Canada and the influence of Hurricane Erin, as reported by the Washington Post.
This weather pattern is bringing significantly cooler overnight lows to the state. Southern Iowa is forecast to experience lows between 50 and 60 degrees Fahrenheit,while northern Iowa could see temperatures drop as low as 40 to 50 degrees Fahrenheit. These cooler temperatures are expected to persist through August 28th.
Will the Fall Feeling Last?
The respite from summer heat is expected to be temporary. Temperatures are predicted to climb back into the 80s by the end of August. Long-range forecasts suggest a warmer-than-usual start to fall for the Heartland.Both the Farmer’s Almanac and the Old Farmer’s Almanac predict above-average temperatures for the upcoming season. The Old Farmer’s Almanac specifically forecasts an average September temperature of 69 degrees fahrenheit and an average October temperature of 57 degrees Fahrenheit for the region.
This early taste of fall serves as a reminder of the approaching seasonal change, even as summer’s warmth lingers on the horizon.
Kate kealey is a general assignment reporter for the Des Moines Register. Reach her at kkealey@registermedia.com or follow her on Twitter at @Kkealey17.
