July 30, 2009
July Weather Not So Hot
Month could set record-Columbia now at 72.2, matching 1924 for lowest average temp
COLUMBIA, MO - July weather, usually hot as a firecracker, is on the way to setting new cool records, said Pat Guinan, University of Missouri Extension climatologist.
In Columbia, temperatures the first 22 days of July averaged 72.2 Fahrenheit, putting the month so far in a tie with 1924 as the coolest July in 121 years of weather records.
"We've had only one day with a 90-degree high temperature," Guinan said. "But we set two new morning-low records at the 56-degree mark. I have to go back to 1994 to find a previous record-breaking low temperature in July."
It's not just Columbia. The whole state has felt below-normal temperatures, with averages running at minus 4 to minus 5 degrees from normal, he said. "While Missouri is cool, states to the north and northeast, the heart of the Corn Belt, have been colder," said Guinan, who tracks crop weather for the MU Extension Commercial Agriculture Program.
"We may have another 90-degree day, but then go back down for the rest of the month. Even with a few warmer days ahead, we'll likely record one of the 10 coolest Julys on record," he said.
"We are under a northwesterly airflow pattern that brings cool temperatures from Canada. That brings both cool and dry air intrusions, with occasional wet periods, over the Midwest." July's below-normal temperatures in the region are not an indicator one way or another on trends in average global temperatures, he said.
The coolest monthly average records to beat are 1924 with 72.2; 1950, 72.4; 1891, 72.4; 1905, 73.3; and 1904, 73.8.
Guinan maintains a statewide network of automated recording stations that provide local agricultural weather updates on the Internet. Historical records also are available on the site at agebb.missouri.edu/weather.