Gary McManus
Associate State Climatologist
Oklahoma Climatological Survey

The dull beginning to May gave hope to many that Oklahoma's normal severe weather season would bypass the state this year. With only three tornadoes and very little in the way of other severe weather through May 9, that certainly seemed possible. Those hopes were dashed by Mother Nature shortly thereafter, however, and the month became one of the most violent in recent memory. While reports are still preliminary, it appears likely that the count for May will approach, if not exceed, 60 tornadoes. That remains well behind the 90 tornadoes of May 1999, which includes the devastating May 3-4 outbreak that devastated central Oklahoma. However, it stands a chance to eclipse the 61 tornadoes that touched down during May 1961 for second place. It would also best the 59 tornadoes of May 2003. Oklahoma normally sees 20 tornadoes during May and 53 for an entire year.

Plenty of severe weather came associated with the multitude of tornado reports. Hail, severe straight-line winds and flash flooding were also common and damaging hazards. A hailstorm on May 16 cut a swath of destruction from northwest Oklahoma through Oklahoma City with numerous reports of golf ball to softball size hail.

Data from the Oklahoma Mesonet rank the month as the 50th-driest May since records began in 1895 with a statewide average of 4.35 inches of rainfall, a little less than an inch below normal. The southern half of the state was quite dry, especially in southwestern Oklahoma where the deficit for the month rose to 3.12 inches, the 13th-driest May for that part of the state. Ada recorded the most precipitation with 8.65 inches while Retrop in southwestern Oklahoma came in with a paltry 0.73 inches.

Even though the statewide average temperature finished near normal, most regions of the state were anything but. Southeastern Oklahoma experienced its 23rd-warmest May at more than 2.4 degrees below normal while the Panhandle was 1.1 degrees below normal, the 35th coolest for that part of the state. Idabel enjoyed the state's highest average temperature for the month at 72.8 degrees while Boise City was the coolest with a 59.3-degree reading. Tipton had the highest temperature and the state's first triple-digit reading of the year with 100 degrees on May 30. Boise City had the lowest temperature with 28 degrees on May 2.