Iowa Monthly Weather Summary – September 2025
General Summary
Preliminary statewide temperatures averaged 67.1 degrees or 3.4 degrees above normal while precipitation totaled 1.70 inches or 1.78 inches below normal.
Temperatures
Much of Iowa reported precipitation deficits through September with the driest conditions across eastern and northwest Iowa; these deficits were at or above two inches. Swaths of stations in western Iowa reported positive departures in the range of one to two inches. Monthly precipitation totals ranged from 0.22” in Davenport (Scott County) to 8.24” in Mondamin (Harrison County).
Precipitation
Statewide average temperatures in August were above average across all of Iowa with the warmest conditions found in pockets from central to northwest Iowa. Davenport reported the month’s high temperature of 99 degrees on the 13th, 22 degrees above normal. Stanley (Buchanan County) reported the month’s low temperature of 32 degrees on the 7th, which was 19 degrees below normal.
Justin Glisan, Ph.D.
State Climatologist of Iowa
Iowa Dept. of Agriculture & Land Stewardship
Wallace State Office Bldg.
Des Moines, IA 50319
Telephone: (515) 281-8981
E-mail: Justin.Glisan@IowaAgriculture.gov
Weather by Districts
| TEMPERATURE (F) | COOLING DEGREE DAYS | PRECIPITATION (inches) | ||||||||
| September 2025 | September 2025 | Since Jan., 1, 2025 | September 2025 | Since Jan.1, 2025 | ||||||
| DISTRICT | Average | Departure* | Average | Departure* | Average | Departure* | Average | Departure* | Average | Departure* |
| Northwest | 66.0 | +3.5 | 101 | +92 | 814 | +287 | 1.25 | -1.90 | 26.00 | +0.66 |
| North Central | 65.5 | +3.3 | 90 | +83 | 768 | +302 | 2.32 | -1.05 | 29.80 | +3.91 |
| Northeast | 65.3 | +3.2 | 87 | +80 | 741 | +294 | 1.74 | -2.06 | 31.59 | -0.49 |
| West Central | 66.7 | +3.0 | 109 | +89 | 923 | +291 | 3.23 | -0.02 | 28.02 | +2.93 |
| Central | 67.4 | +3.6 | 123 | +101 | 952 | +334 | 2.09 | -1.37 | 30.17 | +2.90 |
| East Central | 67.7 | +3.6 | 135 | +109 | 984 | +346 | 0.97 | -2.68 | 30.75 | -2.77 |
| Southwest | 68.2 | +3.2 | 136 | +97 | 1028 | +253 | 2.09 | -1.36 | 29.71 | -5.74 |
| South Central | 68.9 | +3.9 | 154 | +114 | 1083 | +320 | 2.38 | -1.31 | 30.84 | -2.69 |
| Southeast | 69.1 | +3.7 | 162 | +116 | 1119 | +331 | 1.57 | -2.05 | 31.03 | -3.66 |
| STATE | 67.1 | +3.4 | 120 | +99 | 926 | +311 | 1.70 | -1.78 | 29.69 | -0.49 |
* Departures are computed from 1991-2020 normals. Due to the federal government shutdown, observations are still preliminary.
The weather data in this report are based upon information collected by the U. S. Dept. of Commerce, NOAA National Weather Service.
