Drought in Iowa

As of the U.S. Drought Monitor week valid August 25, 2026, 19.6% of Iowa was in moderate drought or worse and 30.5% was at least abnormally dry. Those are the USDM's own published area percentages, republished here as numbers with attribution. The map itself is produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the U.S. Department of Agriculture, NOAA and NASA and is released every Thursday morning for conditions valid the preceding Tuesday, so check droughtmonitor.unl.edu for the live map.

Because the water and the growing season arrive together. Only 10.9 percent of the year's precipitation at Des Moines falls Dec to Feb, so there is no winter surplus to draw on. USGS puts it this way for a state with a similar problem: "The amount of rain and snow also varies with the seasons. In Georgia, most of the yearly precipitation falls during winter, early spring, and in July. Even if the total amount of rainfall for a year is about average, rainfall shortages can occur during a period when moisture is critically needed for plant growth, such as in the early summer."

They are the U.S. Drought Monitor's five categories, from D0 Abnormally Dry through D1 Moderate, D2 Severe, D3 Extreme and D4 Exceptional Drought. D0 is not itself drought: it is the band a place passes through going in and coming out. The category descriptions and the map are the work of the National Drought Mitigation Center at the University of Nebraska-Lincoln, the U.S. Department of Agriculture, NOAA and NASA, and the authoritative definitions are on droughtmonitor.unl.edu, alongside the map itself.

On the U.S. Drought Monitor record, which opens January 4, 2000, the deepest week was September 19, 2023, when 5% of Iowa was in D4 Exceptional Drought or worse. That is USDM's own weekly area figure, not a ranking of ours, and it covers only the satellite era of drought monitoring: Iowa droughts before 2000, including the 1930s and 1950s, are outside this record entirely.

This page reads 3 USGS streamgages in Iowa live when it loads, including Mississippi River at Clinton, IA, and compares today's daily mean discharge against USGS's own published percentiles for that same calendar day over the gauge's full period of record. Nothing is scored or rated by us. USGS notes that streamflow lags rainfall: "The first evidence of drought usually is seen in records of rainfall. Within a short period of time, the amount of moisture in soils can begin to decrease. The effects of a drought on flow in streams and reservoirs may not be noticed for several weeks or months. Water levels in wells may not reflect a shortage of rainfall for a year or more after a drought begins (Moreland, 1993)."

Usually not, and USGS explains why better than we could. On a shower: "A light to moderate shower will probably only provide cosmetic relief. It might make folks feel better for awhile, provide cooling, and make the vegetation perk up. During the growing season, most of the rain that falls will be quickly evaporated or used by plants. Its impact is short term." On the rain that actually helps: "Soaking rains are the best medicine to alleviate drought. Water that enters the soil recharges ground water, which in turn sustains vegetation and feeds streams during periods when it is not raining. A single soaking rain will provide lasting relief from drought conditions, but multiple such rains over several months may be required to break a drought and return conditions to within the normal range."

NOAA's National Integrated Drought Information System defines it this way: "Flash drought is simply the rapid onset or intensification of drought. It is set in motion by lower-than-normal rates of precipitation, accompanied by abnormally high temperatures, winds, and radiation. Together, these changes in weather can rapidly alter the local climate." It matters because it breaks the usual assumption that drought is slow. A place can go from normal to severe inside a few weeks when heat and wind pull moisture out of the soil faster than it is replaced.

Three places, kept apart. The drought category percentages are the U.S. Drought Monitor's own published statistics, produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the U.S. Department of Agriculture, NOAA and NASA, republished here as numbers with attribution and refreshed weekly. The precipitation normals are NOAA NCEI's published 1991 to 2020 climate normals; the driest month, the driest three month run and the state rollup are our own reductions of those published monthly values and are labelled as ours everywhere they appear. The river readings are live from USGS Water Data for the Nation.