Oklahoma just experienced its warmest December since state records began in 1895. According to the Oklahoma Mesonet, temperatures averaged more than 10 degrees above normal for the month. State Climatologist Gary McManus says that's unusual.
"For a monthly average to beat the temperature by more than five degrees, it’s just really not done," said McManus.
December 2021 also became the fourth warmest climatological winter month since statewide records began, just a few tenths of a degree behind the top spot in February 1954.
So, what contributed to the unprecedented warmth? McManus cites a few factors, including climate change.
"We have La Niña out in the equatorial pacific, which tends to bring us a little bit warmer than normal weather. And then we just had a sticky pattern where that jet stream was pushed farther to the north — the strong polar vortex keeping all the arctic air trapped up there in the polar region. And then, of course, there’s the background warming that we’re seeing over the last few decades going on across the globe."
In addition, drought conditions deteriorated across Oklahoma as the year came to a close. According to the U.S. Drought Monitor, drought increased from 61% of the state at the end of November to 90% at the end of December.
While the winter months are typically Oklahoma's driest time of the year, McManus says to have drought this severe in the season is uncommon.
"The problem is we had such a dry antecedent period before the winter months. When we amp the temperatures up 10 degrees above normal for December and bring in all that wind that also accelerates the drought intensification process."
Chances for immediate relief from drought appear slim according to the Climate Prediction Center’s January precipitation outlook, which indicates increased odds of below normal precipitation across the western two-thirds of the state.
