(KIWA Staff Photo)Northwest Iowa (Sioux County Radio) — Northwest Iowa received welcome rainfall last week as several storm systems crossed the region and Iowa recorded its wettest week of the 2026 growing season.
While most northwest Iowa totals remained below the statewide average, the moisture followed several comparatively dry weeks and arrived as corn and soybeans continued moving through late-summer development.
A precipitation map in the latest Iowa Crop Progress and Condition Report shows much of Lyon, Sioux, O’Brien, and Osceola counties received 0.2 to 1.5 inches of rain between August 10th and 16th. Higher totals fell closer to Sioux City and south of the four-county area.
Northwest Iowa Below Statewide Rainfall Average
The statewide average was 2.60 inches — nearly triple the weekly normal of 0.88 inch. Much of central Iowa received 2.5 to 5 inches, pushing the statewide average higher.
Although northwest Iowa did not receive the soaking rainfall recorded elsewhere, the week still brought additional moisture to an area that had remained drier in previous reports.
The newest report also includes rainfall that moved through northwest Iowa after the cutoff for the previous week’s report.
Iowa Secretary of Agriculture Mike Naig said last week’s weather brought several rounds of storms across Iowa, including a derecho that developed in eastern Iowa before moving into the eastern Corn Belt.
Weekly rainfall totals ranged from 0.36 inch at New Market in Taylor County to 9.45 inches at Wapello in Louisa County.
Crop Conditions Remain Strong Statewide
Iowa farmers had 3.3 days suitable for fieldwork last week — 1.8 fewer days than the same week last year.
The report does not provide crop-condition or soil-moisture ratings for northwest Iowa. Statewide, both corn and soybeans were rated 78% good to excellent.
Corn development remained slightly ahead of last year:
- 99% silked
- 83% in dough stage (six points ahead of last year)
- 26% dented (one point ahead)
Soybean development matched last year:
- 96% blooming
- 82% setting pods
Other statewide highlights:
- Oat harvest is 96% complete (six points ahead of last year)
- Pasture conditions are 67% good to excellent
Topsoil moisture:
- 64% adequate
- 17% surplus
- 15% short
- 4% very short
Subsoil moisture:
- 63% adequate
- 11% surplus
- 21% short
- 5% very short
Because rainfall was unevenly distributed, statewide moisture ratings may not reflect conditions in far northwest Iowa.
Several Storm Systems Cross Iowa
Multiple storm systems crossed western and northern Iowa during the reporting period.
- Thunderstorms expanded across northern Iowa early Tuesday.
- Another line entered western Iowa Wednesday morning.
- A broader system covered much of the state Thursday, producing several severe and tornado-warned storms in western and central Iowa. No tornadoes were observed from that system.
- Additional storms developed Thursday night in west-central Iowa and expanded northward.
- The heaviest rainfall generally remained south and east of far northwest Iowa.
A derecho in eastern Iowa Tuesday produced a 75-mph wind gust at Independence. Two EF-1 tornadoes developed near Greeley in Delaware County, damaging vegetation and outbuildings.
Temperatures remained above normal across northwest Iowa. The report’s map shows much of the region averaged 4 to 6 degrees warmer than normal.
Iowa’s statewide average temperature was 76.7 degrees, or 4.8 degrees above normal. Temperatures ranged from 48 degrees at Greenfield to 95 degrees at Lamoni.
