Iowa saw a clear sign that fall is approaching this week, as several locations recorded their daily high temperatures in the early morning hours, a rare occurrence for September. Iowa Environmental Mesonet data shows this typically happens only a few times each year and is more common during cooler seasons.
Meteorologists say the unusual timing reflects the passage of robust cold fronts, bringing significant changes in air masses across the state. Early-morning highs like these indicate that summer warmth is giving way to autumn.
While no severe weather was reported, the shift serves as a reminder that cooler mornings and crisp fall days are on the way for Iowans.
