September weather tables for Iowa look more like something you’d see in southern California than the landlocked midwest. State Climatologist Harry Hillaker says the month is notable for its lack of extremes. Hillaker says the highest official temperature recorded in the state was 86 degrees in Pocahontas on the 16th and 18th and Sibley on the 18th.
“Eighty-six is the lowest September maximum temperature ever in Iowa going back in the record books, it’s always gotten warmer than that at some point in the month every other September that we have records for,” Hillaker says. Hillaker says the range between the highest and lowest temperatures for September also set a record.
He says the last two days of the month had an official low temperature of 32 degrees in Onawa, Guthrie Center and Swea City. “The overall range of temperatures from 32 to 86 (degrees) is the smallest we’ve ever had during the month September,” Hillaker says, “some people have been kind of calling this San Diego weather, which is kind of the case.” Official weather records have been kept for 137 years.
Hillaker says the overall temperature for September average one degree higher at 63.9 degrees. Hillaker says it’s on the third month this year that the temperatures have averaged warmer than normal with February and March the other two. Rainfall for September averaged one-1.71 inches — about one half inch below normal.
Hillaker says some areas were much dryer than normal, but some places did have above normal rainfall. He says Sioux City was the wettest city, with and average of 4.5 inches of rain, with a few areas of central and southeast Iowa had normal rainfall. Hillaker says several areas of the state did not get any rain in the first few weeks of the month. With nine months of the year in the weather record books the state is a little cooler and wetter.
Hillaker says temperature wise the state is running at1.3 degrees cooler than normal and the rainfall is right at one inch greater than normal. He says though much of northwest Iowa is much drier than normal, while east-central and south-east Iowa have been much wetter than normal. Hillaker says the state right now is around the 31st coolest ever, and the 39th wettest.