Slightly more than two months after Oklahoma City tied for its warmest temperature on record, the city officially recorded its earliest autumn freeze.
Such is the highly variable weather of Oklahoma.
On Aug. 3, the high temperature was 113 degrees. On Monday, the temperature was 31 degrees at 5:52 a.m. at Will Rogers World Airport.
And the forecast from the National Weather Service, Norman calls for a few days now of highs possibly in the 80s. Add to this the drought with a few rains tossed in as of late.
Dennis Martin, an Oklahoma State University Extension turf grass specialist, said when looking at the effects of these weather swings, it's important to consider the short-term but also the long-term.
In Oklahoma City for example, there was pretty good recovery from the drought conditions of 2011 through the winter and into early spring.
There was very little in the way of cold weather through the winter and that led into an even warmer spring, finishing as the warmest on record for Oklahoma City, more than 5 degrees above normal.
Temperatures only dropped below freezing one day from March to May, a 29 degree reading on March 4.
“The rainfall picked up considerably during March and April, and Oklahoma City recorded 10.95 inches over the two months,” said Gary McManus, of the Oklahoma Climatological Survey. “Many thought the drought had ended, and according to the U.S. Drought Monitor, Oklahoma City was in the clear.
“The rains suffered a reversal during May, however, a slowdown that would last through August and allow drought to return in full force.”
Only 7.7 inches of rain fell from May through August, more than 8 inches below normal. Also, the heat returned as temperatures reached triple-digits on 23 of 24 days from July 18 to Aug. 9.
But then again, this week, Oklahoma City had its earliest official autumn freeze.
“What these early frosts typically do, if there's any benefit to them at all, is that they knock the crab grass back,” Martin said. “Crab grass kind of takes it on the chin even more so than Bermuda grass. Now if we get a little bit of rainfall, even if it warms back up, the Bermuda's been set back and if the lawns are thin from drought-stress, then often times we have tremendous winter annual weed problems, especially if we would happen to get a few key rainfall events.”
Martin said many people last year were commenting how bad the spring weed problem was and that's because of a mild winter. There was a little rain early, but the lawns were thinned by the drought last year.
“It's not only what this extreme did in late summer, fall and into winter, but how you manage the lawn next spring,” Martin said.
The U.S. Drought Monitor report released Thursday showed 80.57 percent of Oklahoma in extreme to exceptional drought.
A broader look
Oklahoma City has experienced some wild swings in weather from fall 2009 through the fall of 2012.
The fall of 2009 was dominated by a very cool and moist October in areas of the state, McManus said. The weather turned dry after that until the Christmas Eve blizzard. That storm had a record one-day total of 13.5 inches of snow to go along with winds of up to 60 mph, he said.
There was more to come. Oklahoma City experienced its fifth highest seasonal snowfall totals in its history with 23.2 inches. The first couple of weeks in January 2010 had some of the coldest weather the state had experienced in more than a decade. Temperatures fell below zero in some parts of the state, and into the single digits in Oklahoma City. The temperature in Oklahoma City fell below freezing Jan. 2 and didn't rise above 32 degrees until Jan. 6.
“What we had in the spring of 2010 was the worst winter kill of Bermuda grass since spring of 1990,” Martin said. “Now if you carry that into the summer of 2010 in some of the lower maintenance lawns, folks were waiting and waiting for things to green up and they didn't realize they had winter kill.”
So he said that many Bermuda lawns he looked at that fall hadn't been able to recover. Weather was very diverse in 2011, including the hottest summer on record in the United States in terms of statewide temperature.
“So there are some lawns around the state where this damage goes all the way back to the winter kill of 2010, and they've never had an opportunity to repair since if they had low intensity management, didn't fertilize or didn't irrigate,” he said.
“That's why those management practices are so essential for reliability because if you just put Bermuda out there, sure it survives, but the difference between surviving and thriving can be quite great.”