Iowa corn and soybean crops continue in a pattern of later-than-normal development, thanks to the unprecedented late planting this year. The weekly statewide USDA survey for the week ending July 7 provides the latest update, as the corn crop is beginning to move into the critical pollination period.

“Slightly above-average rainfall combined with consistently warmer weather has given crops across the state a boost,” says Iowa Secretary of Ag Mike Naig. “Though some areas had below- average rainfall, soil moisture conditions remain adequate to surplus.”

The complete weekly Iowa Crop Progress and Condition Report is on USDA’s site at nass.usda.gov.  

Crop report

While parts of Iowa experienced heavy rain, overall it was a hot, dry week, allowing farmers to get fieldwork done during the week ending July 7, according to the USDA’s National Ag Statistics Service. Statewide there were 4.6 days suitable for fieldwork. Activities included planting, harvesting hay, spraying and applying nitrogen.

Topsoil moisture rated 0% very short, 4% short, 80% adequate and 16% surplus. Subsoil moisture condition was 0% very short, 2% short, 77% adequate and 21% surplus.

Statewide, 1% of the corn crop has begun to silk, over a week behind last year and the five-year average. Corn condition statewide declined to 61% good-to-excellent. Soybean emergence reached 96%, two weeks behind average. Seven percent of Iowa’s soybean crop has started to bloom, 12 days behind last year and 10 days behind average. Soybean condition rates 64% good-to-excellent.

Iowa’s oat crop is 92% headed, a week behind last year and six days behind average. And, 28% of the crop has started coloring, six days behind average. Oat condition rates 61% good-to-excellent.

The first cutting of alfalfa hay is 94% cut, nearly a week behind average. Second cutting of alfalfa hay reached 12% statewide, 11 days behind average. Hay condition rates 62% good-to-excellent. Pasture condition rates 69% good-to-excellent. Livestock experienced some stress due to heat. Feedlots continue to dry out.

Weather summary

The first week of July brought unseasonable warmth across Iowa with the average statewide temperature of 77.1 degrees, 3.4 degrees above normal, says Justin Glisan, IDALS state climatologist. Showers and thunderstorms were reported on multiple days with parts of northwest Iowa receiving one to three inches of above average rainfall. Sections of eastern Iowa also observed unseasonable wetness, from 1 to 2 inches.

An intense squall line moved north to south through eastern Iowa late Sunday (June 30) afternoon producing severe wind across 20 counties, causing tree and structural damage. Sustained wind gusts varied from 58 mph in Burlington (Des Moines County) to 76 mph in Dubuque (Dubuque County). Heavy rain with stronger storms was reported at Guttenberg Lock and Dam (Clayton County) and Waucoma (Fayette County); these stations saw 1.47 inches and 1.35 inches, respectively.

Showers and storms skirted the Iowa-Minnesota border for much of Monday (July 1) ahead of a low-pressure system in Nebraska. As the low moved east, a line of strong thunderstorms formed in northwest Iowa. These slow-moving storms produced locally heavy downpours and flash flooding in some locations. Eleven stations reported totals above 2 inches, with three stations above 3 inches; Orange City (Sioux County) reported 3.62 inches.

A stationary front across central Iowa forced thunderstorms on Tuesday. Storms began popping up in late afternoon and intensified into the evening as they moved into eastern Iowa. Rain totals were heaviest in west-central Iowa. Wednesday saw similar storms pop up along the existing boundary, transitioning south and east as the day progressed. Locally heavy rain fell along isolated lines of strong storms.

Two-day rain totals were greatest across the central west-to-east third of Iowa with 66 stations reporting over an inch; 9 stations had over 3 inches in central Iowa with a Boone County station getting 5.13 inches. Statewide average rainfall was 0.51 inch, 0.19 inch above average.

Two waves of showers and storms moved across northern Iowa on Independence Day. Rain totals were in the general range of a quarter of an inch to over 2 inches. Cherokee (Cherokee County) reported 2.39 inches, while Ionia (Chickasaw County) reported 2.11 inches. Temperatures were 3 degrees warmer than normal statewide with highs in the mid to upper 80s; eastern Iowa reported lower 90s.

Another line of storms moved into northwest Iowa the morning on July 5^, though it quickly dissipated in the afternoon. Rain totals ranged from 0.13 inch in Spirit Lake (Dickinson County) to 0.91 inch in Sibley (Osceola County). Isolated storms re-fired in eastern Iowa in the evening with locally heavy accumulations.

Stations across northeast Iowa reported rainfall above one inch; Waukon (Allamakee County) received 2.56 inches. Daytime highs were in lower 90s in eastern Iowa, up to 6 degrees above average. The rest of Iowa had seasonal conditions under partly cloudy skies.

Weekly temperature below average

Saturday was slightly cooler than normal with cloud cover that gradually dissipating through the day. Highs were in the upper 70s and lower 80,s while overnight lows into Sunday (July 7) cooled into the 60s under clear to partly cloudy skies.

Weekly rain totals ranged from no accumulation in Corning (Adams County) to 5.55 inches in Ogden (Boone County). Statewide weekly average precipitation was 1.13 inches, slightly above the normal of 1.08 inches. The week’s high temperature of 97 degrees was reported on July 1 in Cherokee (Cherokee County), 12 degrees above normal. Cresco (Howard County) had the week’s low temperature of 56 degrees on the July 7, 3 degrees below average.