Most of Iowa had multiple days of much needed rain, which left just 1.4 days suitable for fieldwork during the week ending Sept. 13, according to the USDA, National Agricultural Statistics Service. Field activities included harvesting corn for silage, moving old crop grain stocks, and preparing equipment and bins for harvest.
Topsoil moisture condition across the state rated 12 percent very short, 21 percent short, 59 percent adequate and 8 percent surplus. Ratings in west central Iowa were 19 percent very short, 30 percent short, 50 percent adequate and 1 percent surplus, much improved from a week earlier
Subsoil moisture conditions statewide rated 20 percent very short, 31 percent short, 46 percent adequate and 3 percent surplus. Ratings in west central Iowa were 47 percent very short, 38 percent short, and 15 percent adequate.
Corn was 90 percent in or beyond dent stage, more than two weeks ahead of the previous year and five days ahead of the 5-year average. Forty-five percent of the crop has reached maturity, almost three weeks ahead of last year and one week ahead of average. Corn harvest for grain has begun across much of the state with 1 percent of the crop harvested. Corn condition rated 42 percent good to excellent, a drop of 1 percentage point from the previous week.
Soybeans coloring or beyond advanced to 79 percent. That is more than weeks ahead of last year and one week ahead of average. Soybeans dropping leaves reached 41 percent this week, two weeks ahead of last year and six days ahead of average. Soybean harvest began in some areas with 1 percent of the crop harvested statewide. Soybean condition rated 48 percent good to excellent.
Alfalfa hay third cutting was 96 percent complete, over a month ahead of last year and 18 days ahead of the 5-year average. Pasture condition improved 5 percentage points this week although still just 17 percent good to excellent. Pastures are greening up as a result of receiving much needed rain. Cattlemen continued supplemental feeding of hay.
Iowa preliminary weather summary provided by Justin Glisan, Ph.D., state climatologist Iowa Department of Agriculture and Land Stewardship – A significant shift in the storm track brought the wettest week of the reporting season to Iowa. More rain fell across the state than in the month of August with a vast majority of reporting stations observing positive departures; eastern Iowa reported up to five inches more than normal rainfall. Unseasonably cool conditions also blanketed the state due to extended rainfall and cloud cover. Temperatures were up to 14 degrees cooler than normal with the statewide average temperature at 55.4 degrees, 11.3 degrees below normal.
Thunderstorms with locally heavy rainfall were present in eastern Iowa Sunday afternoon, Sept. 6, with light rain stretching into central Iowa. As the system cleared, mostly sunny skies returned and daytime highs pushed into the upper 80s and low 90s. Northerly winds built in overnight, signaling a transition to a more active storm track with lows on Monday ranging from the mid 50s north to mid 60s south. Clouds increased through the day holding highs in the upper 60s and low 70s in the state’s northern half. A stationary front in southern Iowa allowed temperatures to rise into the upper 70s. Thunderstorms began forming along this boundary during late evening and quickly expanded to cover much of southern Iowa.
A secondary complex of thunderstorms associated with an upper level disturbance moved into northwestern Iowa overnight. The large-scale flow configuration brought waves of showers and thunderstorms over the next several days. On Tuesday, Sept. 8, temperatures were well below average and the coldest of the season, generally in the upper 40s and low 50s with the statewide average high temperature of 52 degrees, 26 degrees cooler than normal. Multiple stations reported record low high temperatures for the date, breaking records from the late 1800s. Des Moines (Polk County) and Waterloo (Black Hawk County) both observed 51 degrees, besting their records of 54 and 58 degrees, respectively, set in 1898. Cloud cover held morning lows in the mid to upper 40s.
Two-day rain totals reported at 7 am on Wednesday, Sept. 9, showed widespread amounts of at least an inch across a majority of reporting stations with nearly 100 stations observing more than two inches. The highest totals were found in eastern Iowa ranging from 3.02 inches in Marengo (Iowa County) to 3.79 inches at Salem 1 S (Henry County); the statewide average rain total was 1.50 inches.
Rain showers continued through the day with a lull during the late evening hours before another round of showers moved into southwestern Iowa overnight into Thursday, Sept. 10. The rain shield spanned most of the state and slowly pushed out of eastern Iowa during late afternoon. Cloudy and cool conditions persisted with patchy mist and drizzle as temperatures remained in the 50s. Much of the central southwest to northeast one-third of Iowa received rainfall in the 0.50 to 1.00 inch range. Only a few stations in northwest Iowa did not report measurable rain. Elma (Howard County) observed 1.73 inches while the statewide average was 0.56 inch.
Dreary conditions continued through Friday with widespread, persistent rainfall across Iowa’s eastern half. Western Iowa also saw wet conditions, though spottier than in the east. Afternoon temperatures were warmer than the last few days, peaking in the upper 50s and low 60s, still 10 – 20 degrees below average. Rain gauge measurements at 7 am on Saturday, July 12, had the highest totals in eastern Iowa, where one to two inch totals were frequently found; more than 25 stations reported two inches or more with a gauge in Hopkinton (Delaware County) collecting 2.86 inches. Totals across the state’s central one-third were in the 0.30 to 0.75 inch range with lighter amounts towards the Iowa-Nebraska border. Spotty rain showers continued into the late night hours as the upper level low pushed east, though totals were general light. Clouds began to decrease overnight into Sunday with low temperatures in the upper 40s and low 50s.
Weekly precipitation totals ranged from 0.41 inch in Rock Rapids (Lyon County) to 6.88 inches at De Witt 4 (Scott County). The statewide weekly average precipitation was 3.12 inches, almost four times the normal of 0.84 inch. Little Sioux 2NW (Harrison County) reported the week’s high temperature of 97 degrees on Sept. 6, 18 degrees warmer than normal. Holstein 5 NNW (Ida County) reported the week’s low temperature of 39 degrees on Sept. 9, 12 degrees cooler normal.
