According to data from the Oklahoma Mesonet, the statewide average rainfall total for May was 4.9 inches, about 0.3 inches below normal. That ranks the month as the 54th wettest since 1895. A band from south central through central and northeastern Oklahoma recorded from 9 to 11 inches of rainfall.
Most of the western third of the state recorded less than 2 inches, however, with much of the Panhandle seeing less than a quarter of an inch. Although the spring season had a rather unremarkable statewide average at 10.65 inches, about an inch below normal, the stark contrast between western Oklahoma and the rest of the state was evident in the details. The Panhandle experienced its fourth driest spring on record while central Oklahoma had its 15th wettest.
The exaggerated moisture difference produced obvious changes to the U.S. Drought Monitor by month’s end. Extreme and exceptional drought increased through the western third of the state while drought was eliminated across much of central and eastern Oklahoma. May’s final Drought Monitor map showed about 41 percent of the state being drought free but 27 percent under the extreme-exceptional categories.
The June outlooks from the Climate Prediction Center indicate increased odds of below-normal precipitation and above-normal temperature across western Oklahoma, particularly in the Panhandle. The outlooks are inconclusive across the rest of the state.
The outlooks for the summer season call for increased odds of below-normal rainfall across the western half of the state and above-normal temperatures across Oklahoma. CPC’s latest U.S. Seasonal Drought outlook predicts improving drought conditions across most of Oklahoma through August, with the exception of the extreme western third of the state and the Panhandle. Drought is expected to persist or intensify in those areas.
Gary McManus is the associate state climatologist with the Oklahoma Climatological Survey.