Iowa Weekly Growing Season Report

_{Preliminary weather summary for the week Sept. 8-14, 2025}

Temperatures were well above average throughout the reporting period, with positive departures on the order of three to six degrees. The statewide average temperature was 69.1 degrees, 4.0 degrees above normal. Unseasonable dryness also continued into the middle of September, with numerous stations reporting no rainfall from central to southeastern Iowa.

Sunday (7th) afternoon was pleasant, with variable winds, mostly sunny skies and temperatures ranging from the mid 60s to the low 70s. Winds shifted to a southerly direction into Monday (8th), with morning lows in the upper 40s and low 50s. Daytime temperatures held in the 70s with partly cloudy skies in western Iowa. Scattered showers moved into southwestern Iowa by daybreak on Tuesday (9th), expanding into northern Iowa through the day. Rainfall totals were generally light, though a few stations reported higher amounts; 0.61 inch was observed in Rock Rapids (Lyon County), while Persia (Harrison County) collected 0.80 inch. Afternoon conditions were cloudy in northern Iowa with highs in the low 70s, while farther south, temperatures were several degrees warmer. Showers continued into the early morning of Wednesday (10th) in northern Iowa, with many locations observing at least 0.50 inch. The highest totals were in north-central to northeast Iowa, ranging from 0.81 inch in Stanley (Buchanan County) to 0.96 inch in Osage (Mitchell County). Daytime conditions were sunny, with temperatures rising into the low 80s under light and variable winds.

Thursday (11th) began a stretch of increasingly warm days, with temperatures rising into the upper 70s in the north to the mid 80s in the south. Skies remained clear into Friday (12th), with southerly winds and highs in the 90s across southeastern Iowa. Scattered showers developed in western Iowa and moved east through the day, leaving very light totals at several stations; Swisher (Johnson County) registered 0.01 inch, while Le Mars collected 0.07 inch. Saturday (13th) morning was unseasonably warm, with lows in the mid to upper 60s at most locations under clear skies. Afternoon conditions were hot, with highs in the mid to upper 90s; the statewide average temperature was 93 degrees, 17 degrees above normal. Patchy fog was reported in eastern Iowa around sunrise on Sunday (14th), with light east to southeasterly winds and temperatures in the mid to upper 60s.

The weekly precipitation totals ranged from no accumulation at many Iowa stations to 1.22 inches in Elma (Howard County). The statewide weekly average precipitation was 0.10 inch, while the climatological normal is 0.85 inch. Davenport (Scott County) reported the week’s highest temperature of 99 degrees on the 13th, 22 degrees above normal. Several stations reported the week’s lowest temperature of 35 degrees on the 8th, on average 16 degrees below normal.