The average temperature for the first six months of the year was the warmest on record for Oklahoma, and more warm conditions are likely on the way, a state climatologist said.
Between January and June, the state's average temperature was 60.1 degrees. That average temperature tops the previous record of 58.9 degrees, set in 2006, and places the state about four degrees above normal for the period, associate state climatologist Gary McManus said.
That average was driven in large part by a warmer winter than the state usually experiences, McManus said. Last winter ranked as the ninth-warmest on record in Oklahoma, with an average temperature of 41.7 degrees. Average temperature records date to 1895.
“It wasn't an extremely hot winter,” McManus said. “It just didn't get that cold.”
The pattern of warmth continued through the spring, he said. Like the winter before it, this past spring proved to be the warmest on record.
The trend goes back more than two years, he said. Of the past 27 months, 22 have been above the state's normal temperature.
McManus said he expects the trend to continue.
Rainfall below normal
In the month of June, Oklahoma received 2 inches of rain below the state average. Drought conditions are increasing across much of the eastern portion of the country, he said, and for the first time since late 2011, the entire state is now considered at least “abnormally dry,” a designation that identifies an area as one step below drought conditions.
Above-average temperatures are “almost a certainty,” McManus said.
Typically, he said, Oklahoma summers come in two varieties: hot and wet, or extremely hot and dry. At the moment, he said, the state appears to be headed for the latter.
“A typical Oklahoma summer is hot anyway,” he said.
Typically, he said, the state sees temperatures in the low- to mid-90s during the hottest months of the summer, generally July and August.
This summer, he said, Oklahoma has already seen triple-digit temperatures. The highest so far occurred June 26 and 27, when Buffalo and Freedom, in northwestern Oklahoma, saw highs of 112 degrees.
The persistent heat and drought conditions are the results of a number of factors, McManus said. Chiefly, he said, the conditions are due to natural variability from one year to the next. The state also is feeling the lingering effects of the La Nina system that dissipated this year.
Oklahoma is seeing a decades-long trend of temperatures rising slowly as a result of climate change, McManus said. But he doesn't think that trend is playing a major role in the weather phenomena the state is currently experiencing.
“I think that we would probably have been setting all these records anyway,” he said. “There are different things that come into play.”