The Ottumwa Courier

September 9, 2013

Heat back, but not for long

By MATT MILNER
Courier staff writer

---- — OTTUMWA — Scorching heat is back, but forecasters think it will be short-lived.

Highs in Iowa hit triple-digits. Such intense heat is very unusual for this time of year, but it has happened before. Ottumwa's record for Sept. 9, a blistering 102, survived the day.

And that's not particularly close to the all-time record for Iowa in September, though. State Climatologist Harry Hillaker said that's 107, which was set three times between 1913 and 1939.

So what's happening? Hillaker said this is only the seventh September to see triple digits since 1980. And most of those incidents were at the start of the month, not this far in.

“It's pretty unusual,” he said. “In Des Moines we're already beyond the latest triple-digit reading here.”

Late September scorchers are even rarer, but they have happened. The latest Iowa has hit 100 degrees is Sept. 28, but that happened back in 1953.

The National Weather Service says much of Iowa was expecting near-record highs Monday, and the continuing drought means an elevated fire danger. There's a chance for rain Tuesday night and Wednesday as the heat breaks, but it's not a strong chance.

Ottumwa has not seen measurable rain in more than a month, with the most recent rainfall on Aug. 6-7.

The lack of rain this summer has also led to a very, very short tornado season for Iowa. While tornadoes are still possible, the chances of such severe weather will drop dramatically as the fall arrives.

The 2013 severe weather season could go down as the shortest in Iowa history. It began with the longest tornado drought in history. The record streak, which began in 2012, ended May 19 at 359 days.

Only 15 tornadoes have hit Iowa this year. If that holds, it would break the old record of 16 set in 2012. The 2013 tornado season will also have lasted a scant 38 days. The old record was 40 days set in (you guessed it) 2012.

Hillaker cautioned that tornadoes can and do happen in the fall and winter months.

“It's still possible that we can get them later,” he said. In fact, about half the years have a tornado after Sept. 1.

But the numbers drop off rapidly. June is the peak month for tornadoes in Iowa since 1980, and the numbers plummet after that. The highest number of tornadoes after Sept. 1 is only 13. That took place back in 2005.

Even a significant outbreak would be hard-pressed to bring Iowa anywhere close to the statewide annual average for tornadoes, which Hillaker said is in the high 40s.