Iowa Weekly Growing Season Report

Preliminary weather summary for the week ending November 10, 2019

Cold conditions continued to grip Iowa during the first full week of November. Average temperatures were coldest across northern Iowa, where departures of 10 to 12 degrees below normal were reported. Iowa’s average temperature was 32.0 degrees, 7.4 degrees below normal. Unseasonably dry conditions were also observed over a majority of Iowa with departures generally between 0.20 to 0.60 inches. Above average snowfall was also observed across northern Iowa. 

A center of low pressure moved through Iowa during Sunday (3rd) afternoon and evening, bringing light rainfall across the state’s northern half. General totals varied from 0.01 inches to 0.03 inches from Des Moines (Polk County) to Waterloo (Black Hawk County) with the highest accumulations across north-central Iowa; Britt (Hancock County) reported 0.30 inches while Elma (Howard County) observed 0.36 inches. With cloudy and rainy conditions across much of the state, daytime highs remained in the mid 40s north to low 50s south. A fast-moving cold front moved across Iowa on Monday (4th) shifting winds to a northwesterly direction with high temperatures reaching into the mid to upper 40s. Cloudy conditions persisted into Tuesday (5th) as overnight lows dipped into the 20s. High pressure moved into the region during the day and was quickly followed by low pressure systems that brought snowfall along the Iowa-Minnesota border through early Wednesday (6th) morning. As the system was exiting eastern Iowa, another round of light snow moved through much of the state’s northern three-quarters. Three to four inches fell across northern Iowa with locally heavier amounts near Decorah (Winneshiek County), where six inches was observed; snow totals tapered off to a dusting towards southern Iowa.

Overnight temperatures into Thursday (7th) plummeted into the single digits across northern Iowa with lows across southern Iowa remaining in the mid to upper teens. The average nighttime temperature was 12 degrees, 20 degrees below average. A dome of high pressure took control across the Midwest during the day with gradually clearing conditions after sunset.  Daytime highs were well below normal, from the mid 20s north to low 30s south. As the high pressure slowly propagated east, winds shifted out of the south, helping highs on Friday (8th) rebound into the upper 30s and low 40s under mostly sunny skies. Saturday (9th) was the warmest day of the month so far as a warm front lifted north across Iowa. Daytime highs in southwestern Iowa reached into the low 60s with mid to upper 50s across much of the rest of the state; mid 40s were reported in northeastern Iowa as cold northwesterly flow around a low pressure in Wisconsin held temperatures below average. The statewide average high was 54 degrees, four degrees warmer than normal. Cloud cover moved back into northern Iowa through Sunday morning (10th) with a northerly wind and lows in the mid to upper 30s, slightly colder than average.

Weekly precipitation totals ranged from no accumulation at multiple stations in southern Iowa to 0.76 inches in St. Ansgar (Mitchell County). The statewide weekly average precipitation was 0.11 inches, while the normal is 0.52 inches. The average snowfall across Iowa was 0.70 inches. The week’s high temperature of 65 degrees was reported on the 9th at Little Sioux (Harrison County), 15 degrees above normal. The week’s low temperature of -3 degrees was reported on the 8th at Cresco (Howard County), 30 degrees below normal. Soil temperatures as of Sunday were generally in mid 30s north to low 40s south.