Iowa Weekly Growing Season Report

_{Preliminary weather summary for the week Sept. 29-Oct. 6, 2025}

Summer-like temperatures blanketed the Upper Midwest last week, with exceedingly dry conditions reported statewide. Temperatures were 12 to 16 degrees above normal, with a statewide average temperature of 72.0°F, 14.7 degrees above normal. Rainfall was sparse, with only a handful of stations reporting measurable but very light totals.

Winds gradually shifted from easterly to southerly through Sunday (28ᵗʰ) afternoon, with daytime temperatures in the mid to upper 80s across much of Iowa. Starry skies continued through Monday (29ᵗʰ) morning, with lows in the 50s and patchy fog across central Iowa. Afternoon highs climbed into the mid to upper 80s under partly cloudy skies and variable winds. Mostly sunny conditions persisted through Tuesday (30ᵗʰ) and Wednesday (1ˢᵗ), with winds returning to a southerly direction and high temperatures in the 80s. Morning lows into Thursday (2ⁿᵈ) held in the upper 50s and low 60s under mostly clear skies. Afternoon conditions continued the unseasonably warm stretch, featuring low relative humidity and highs in the mid to upper 80s.

Much of eastern Iowa dawned cloudy on Friday (3ʳᵈ), with morning temperatures bottoming out in the 60s. Daytime conditions were hot, with the statewide average high reaching 87 degrees, 19 degrees above normal. Overnight skies were generally clear, with stronger southerly winds holding lows in the low 70s northwest to mid 60s southeast; the statewide average low was 62 degrees, 17 degrees above normal. Saturday (4ᵗʰ) was a blustery day with strong southerly gusts and anomalously low dew points, which exacerbated fire weather concerns. Daytime temperatures rose into the upper 80s, as an approaching cold front compressed the large-scale pressure field, pushing sustained wind speeds into the 20–30 mph range; Estherville Municipal Airport (Emmet County) recorded sustained winds of 32 mph with a gust of 47 mph. Clouds increased over western Iowa as the surface boundary approached into the early hours of Sunday (5ᵗʰ). Light rain was reported at a few stations, with totals ranging from 0.01 inch in Sioux Center (Sioux County) to 0.12 inch at the National Weather Service cooperative station in Spencer (Clay County).

Weekly precipitation totals ranged from no accumulation at most Iowa stations to 0.12 inch at two stations in Spencer. The statewide weekly average rainfall was below a measurable threshold, while the normal stands at 0.74 inch. Muscatine (Muscatine County) reported the week’s high temperature of 93 degrees on the 3ʳᵈ, 23 degrees above normal. Osage (Mitchell County) and Spencer recorded the week’s low temperature of 41 degrees on the 29ᵗʰ, about four degrees below normal.