Iowa Weekly Growing Season Report

Preliminary weather summary for the week ending November 20, 2022

Wintertime conditions blanketed Iowa over the reporting period with the first widespread snowfall for the state. General totals were in the two to four-inch range with most stations measuring at least 0.50 inch. Unseasonable coldness also persisted with departures of up to 15 degrees below normal; the statewide average temperature was 23.8 degrees, 13.2 degrees below normal.

Cloud cover gradually cleared through Sunday (13th) afternoon with winds blowing out of the southeast and daytime highs lingering in the upper 20s to mid 30s. Overnight lows into Monday (14th) did not drop appreciably, holding in the upper 20s north to low 20s south as clouds returned. Light snow showers formed over northwest Iowa but dissipated by early afternoon with temperatures still below normal but warming into the low 40s across southern Iowa. A broader shield of light to moderate snow pushed into Iowa overnight, reducing visibilities and creating slick road conditions. Snow continued over much of Iowa through Tuesday (15th) as afternoon conditions remained overcast with temperatures in the 20s. There was a brief lull in snow showers into the evening hours with light snow redeveloping over most of the state, lending to another morning of treacherous driving conditions. Event snow totals measured at 7:00 am on Wednesday (16th) were highest over a north-to-south swath of central Iowa where nearly 120 stations observed at least two inches of wet snow; Mount Ayr (Ringgold County) observed 4.5 inches while an observer in Swea City (Kossuth County) reported 5.9 inches with a statewide average of 1.8 inches. Another wave of light snow moved southeast through the later afternoon and evening hours, leaving behind a few tenths of inch at a majority of stations reporting snow; Webster City (Hamilton County) measured 2.0 inches with 1.5 inches in Algona (Kossuth County).

Thursday (17th) saw blustery northwesterly winds develop with scattered, light snow showers persisting across portions of northern Iowa. Morning conditions were mostly cloudy with lows in the upper teens and 20s; high temperatures peaked around noon before beginning a steep fall through the day and nighttime hours. Pockets of snowflakes continued to fly into Friday (18th) morning with single-digit temperatures in western Iowa while low 20s were reported farther east. Winds shifted to a westerly direction through the day with afternoon temperatures remaining in the upper teens to upper 20s; the statewide average high was 25 degrees, 20 degrees below normal. An upper-level disturbance brought light snow over northern Iowa after midnight with southerly winds and clearing skies in southern Iowa; Sioux City Airport (Woodbury County) picked up 0.2 inch of snow. Blustery northwesterly winds developed through Saturday (19th) with clearing skies and highs ranging from the upper teens north to the upper 20s south. Stars were visible overnight as a swing to southerly winds indicated a shift to warming temperatures. Morning lows reported at 7:00 am on Sunday (20th) held in the teens under mostly clear skies.

Weekly precipitation totals ranged from no accumulation at several southwestern Iowa stations to 1.08 inches in Waterloo (Black Hawk County. The statewide weekly average precipitation was 0.20 inch while the normal is 0.45 inch. Donnellson (Lee County) reported the week’s high temperature of 45 degrees on the 14th, six degrees below normal. Mason City Municipal Airport (Cerro Gordo County) reported the week’s low temperature of five degrees on the 19th, 18 degrees below normal. Four-inch soil temperatures were in the low 30s north to upper 30s south as of Sunday.