BISMARCK, NORTH DAKOTA — Looking at the pattern ahead, there will be a clear west to east divide in Harvest weather conditions, with more frequent rain and limited dry time in the Western Ag Belt and drier conditions, more favorable weather, to the east, according to a Harvest Weather Pattern Set Upforecast from BAMWeather, covering percent of normal rainfall from September 24 through October 1, 2026.
Pierre and Central South Dakota See the Wettest Signal on the Entire Map
If you’re a farmer or rancher near Pierre, South Dakota, you’re looking at rainfall forecast to reach 260 percent of normal for this stretch, the single highest reading anywhere on this map. Combined with a surface low tracking right through the region, this points to a genuinely soggy week and a half ahead, with harvest activity likely facing repeated delays as rain keeps returning to the same fields.
Bismarck, Fargo and Des Moines All Face More Than Double Normal Rain
Across North Dakota, Bismarck is forecast for 210 percent of normal rainfall, with Fargoclose behind at 200 percent. Farther south, Des Moines, Iowa, matches Bismarck almost exactly at 210 percent. If you’re anywhere across this stretch of the Northern Plains and Iowa, expect this period to bring frequent rain risks, as labeled directly on the forecast graphic, making it difficult to find a consistent dry stretch long enough for fieldwork.
Denver, Colorado Springs and Amarillo Also See Well Above Normal Totals
Out toward the western edge of the Ag Belt, Denver and Colorado Springs are both forecast for 210 percent of normal rainfall, while Amarillo, Texas, sits even higher based on the shading near that value on the map. If you’re a producer across eastern Colorado or the Texas Panhandle, this outlook points to the same frequent, disruptive rain pattern affecting the Dakotas and Iowa rather than any relief heading your way through October 1.
Omaha, Topeka and Oklahoma City Round Out the Wet Western Corridor
Farther south along this same corridor, Omaha, Nebraska, is forecast for 155 percent of normal rainfall, with Topeka, Kansas, at 140 percent and Oklahoma Cityeven higher at 180 percent. If you’re farming or ranching anywhere across this stretch of the central and southern Plains, this period looks set to bring meaningfully more rain than typical for early fall, extending the frequent-rain pattern well south of the Dakotas.
Chicago and Milwaukee Sit Right on the Dividing Line
If you’re in Chicago, you’re positioned almost exactly on the boundary between the wetter west and drier east, with rainfall forecast at 50 percent of normal. Milwaukee sits just north at 55 percent. Interestingly, both readings actually point toward drier than normal conditions locally, even though these cities sit at the eastern edge of the broader green-shaded wet zone, illustrating just how sharp this west-to-east transition really is over a relatively short distance.
Indianapolis, St. Louis and the Ohio Valley See Favorable Dry Harvest Weather
East of that dividing line, conditions improve considerably for anyone bringing in a harvest. Indianapolis is forecast for just 20 percent of normal rainfall, with St. Louis at 25 percent. This is the heart of the more frequent dry time, favorable harvest weather zone specifically labeled on the map, meaning producers across the Ohio Valley should see considerably better conditions for getting into the fields compared to their counterparts farther west.
Nashville, Knoxville and the Mid-South See Solid Drier Conditions
Continuing east, Nashville is forecast for 25 percent of normal rainfall, with Knoxvilleslightly higher at 40 percent. If you’re anywhere across the Mid-South, this stretch of days looks like one of the more favorable windows for harvest activity you’ll see this fall, standing in sharp contrast to the soggy pattern gripping the Dakotas and Iowa at the same time.
Toronto, Pittsburgh and the Northeast Also Trend Dry Under High Pressure
A strong surface high, marked with a bold Hon the map, sits directly over the region stretching from Toronto through Pittsburgh, both forecast for just 20 percent of normal rainfall. That high pressure is the driving force behind the favorable, dry conditions extending across this entire eastern half of the outlook, from the Great Lakes down through the Ohio Valley and into the Mid-South.
Richmond and Raleigh See Some of the Driest Readings on the Map
Even farther east, Richmond, Virginia, is forecast for just 30 percent of normal rainfall, while Raleigh, North Carolina, comes in even lower at 15 percent, among the driest readings anywhere on the entire map. If you’re a producer across Virginia or the Carolinas, this period looks set to deliver about as favorable a stretch of harvest weather as this outlook shows anywhere in the country.
What This West-to-East Divide Means for Harvest Planning
For growers across the Western Ag Belt, from North Dakota and South Dakota through Iowa, Nebraska, Kansas and Oklahoma, this outlook points toward a genuinely difficult stretch for fieldwork, with frequent rain riskslikely to force repeated pauses in harvest activity through October 1. Meanwhile, producers across the Ohio Valley, Mid-Southand into the Mid-Atlantic should see a considerably smoother window, with more frequent dry stretches supporting steady progress. Forecasters note more details on how this pattern evolves into October are coming in a separate long-range update.
