Looking back on a weird month of weather

News, Weather

August 1st, 2013 by Ric Hanson

Last month was much cooler and drier than the typical July in Iowa. State Climatologist Harry Hillaker says the month started with some significant heat, but turned unusually cool over the last week. “Overall, temperatures for the month averaged about 1.2 degrees below normal,” Hillaker says. “It ranks as the 30th coolest July in 141 years of records.”

Many locations posted daily record low temperatures between July 28th and 30th. Here in Atlantic, the coldest and record-setting low temperature occurred on July 27th, when we bottomed out at 41-degrees. Average low for the month was 58, whereas the normal average low is 63. The coldest temperature recorded over the month occurred last weekend when Battle Creek, in northwest Iowa, hit 39 degrees. “That’s the first time we’ve reached the 30s anywhere in Iowa in July in almost 30 years,” Hillaker says.

The highest recorded temperature last month was 98 degrees in Keokuk on July 19th. “That 98 at Keokuk is the highest temperature so far in the summer months this year in Iowa,” Hillaker says. “Oddly enough, it’s not the highest temperature of the calendar year. Way back on May 14th, Sioux City reached 106 degrees.” The hottest day in Atlantic, was 92 on July 17th. The average high for the month was 85, which is just one degree shy of normal. Iowa has not reached triple digit temperatures this entire summer.

The statewide average rainfall total for July was 1.76 inches, making it the 9th driest July in state history. Hillaker says sections of north-central and south-central Iowa actually received above average rainfall, but most of the state received very little precipitation. At least one town, Carroll, posted a record dry July with just 18-hundredths of an inch of rain.

Atlantic was also very short on rain last month. We received just 13-hundredths of an inch of rain in July, but that did not break the record set last year, when just a trace of rain fell over the entire month in Atlantic. Normally, Atlantic receives 4.62-inches of rain during the month of July. Year-to-date, we’ve received 18.81-inches of precipitation (Jan.-July, including melted snowfall).

Not a single tornado touched down in Iowa last month. There have been 15 confirmed tornadoes in Iowa this year. That compares to 16 in all of 2012, which was the lowest tornado total in Iowa since 1953.

(Radio Iowa/KJAN weather records)