May

May is considered to be the stormiest month of the year in Oklahoma. Storms during the month commonly produce torrential rainfall, frequent lightning, and numerous tornadoes. The average number of reported tornados for the month of May is 18.5. This number, however, can range greatly, from the 61 tornadoes of 1960, the state’s record, to only 2 confirmed tornadoes in 1988. May is also the wettest month for the state. The monthly average statewide precipitation is 4.94 inches, about half of some of the maximum recorded totals.
 
Top Ten Lists
Top 10 Warmest Oklahoma Mays (Statewide average daily temperatures)
  Top 10 Coolest Oklahoma Mays (Statewide average daily temperatures)
  Top 10 Driest Oklahoma Mays (Statewide average precipitation accumulations)
  Top 10 Wettest Oklahoma Mays (Statewide average precipitation accumulations)
  Top 10 Most Tornadic Oklahoma Mays (Statewide number of tornadoes, all intensities)
  Records for statewide averages extend from 1892, as published by the National Climatic Data Center (NCDC).
 
Daily Facts
 
May 1, 1993
Over 5 inches of rain fell on Drumright overnight with resulting flash flooding causing extensive damage to the downtown area.
 
May 3, 1999
Oklahoma suffered a devastating tornado outbreak on May 3-4. Seventy tornadoes killed at least 44 people in central Oklahoma and Southern Kansas. This outbreak is Oklahoma’s deadliest tornado event since the 1947 Woodward tornado. One tornado produced F5 damage in the Bridge Creek community and across northern Moore and F4 damage in southern Oklahoma City, extending into Del City and Midwest City. A mobile Doppler radar operated by researchers from the University of Oklahoma and the National Severe Storms Laboratory recorded a maximum wind of 318 miles-per-hour in the funnel, but above the level of surface winds.

Storms that struck Dover and Mulhall gained F4 status and also produced fatalities. Additional F3 damage was reported near Apache, between Chickasha and Verden, from Sparks to Stroud, and near Omega and near Short on the morning of the 4th. Tornadoes were reported in 29 counties from late afternoon on the 3rd through mid-day on the 4th.
 
May 3, 1995
Softball-sized hail was reported near Lone Grove and tennis ball-sized hail fell near Friendship and south of Comanche.
 
May 4, 1991
Strong winds from thunderstorms produced wind gusts as high as 85 miles per hour. The high winds caused damage at Chelsea.
 
May 4-5, 2001
Six apparent tornadoes were reported on the evening of the 4th and early morning of the 5th. Small tornadoes were reported in Grady County near Chickasha and Amber, in Comanche County near Geronimo and Pumpkin Center, in Grandfield (Tillman), and near Cordell (Washita). Woodward (Woodward) reported 5.26 inches of rain. Camargo and Leedey (both in Dewey County) reported 4.78 and 4.58 inches of rain, respectively. Street flooding was reported in Elk City (Beckham).
 
May 5-6, 2002
A storm system moved across northern portions of the state on the evening of May 5th and the morning of May 6th. A tornado destroyed a mobile home near Seiling (Dewey) and another was reported in southwestern Ellis County on the 5th.
 
May 6, 2001
Tornadoes were spotted near Noble (Cleveland), Woodford and Ardmore (both Carter), and in Marshall County. Wind damage was reported in Ada (Pontotoc), street flooding afflicted Norman (Cleveland), and two-and-three-quarter inch hail fell in Bryan County.
 
May 6, 1994
Thunderstorms produced softball-sized hail in Okfuskee and Pawnee counties. Locally heavy rain caused flooding in northern Nowata County. Lenapah reported 5 inches of precipitation and Wann received 3.4 inches of rain in 90 minutes.
 
May 8, 1989
A Delaware County tornado traveled approximately 4 miles on the ground, uprooting trees, destroying or damaging several homes and farm buildings.
 
May 8-9, 2003
A series of tornadoes struck Oklahoma City and the surrounding areas on successive days, including an F4 which struck portions of Moore. Damages for the outbreak include: 432 single family dwellings destroyed, 2889 damaged; 5 public buildings with major damage; and more than 100 businesses damaged. Monetarily, damages may exceed $750 million. The injured from these storms total 144, with one fatality attributed to the F3 tornado that struck Oklahoma City on the 9th.
 
May 9, 1996
Strong winds fanned grass fires in Woods and Woodward counties while isolated thunderstorms in the same area produced baseball-sized hail but little precipitation.
 
May 10, 1992
Thunderstorms producing heavy precipitation flooded Tecumseh during the night with 6 inches of rain.
 
May 11, 1999
Oklahoma Mesonet maximum wind reports included 91 miles-per-hour at Mangum and 85 miles-per-hour at May Ranch. These winds were associated with severe thunderstorms.
 
May 11, 1996
Idabel reported a torrential rainfall of 5.35 inches in 24 hours.
 
May 12, 2002
Storms on May 12th brought heavy rains to portions of east-central Oklahoma. Rainfall totals over two inches were reported at Heavener (2.50 inches; Leflore), Wister Mesonet (2.23 inches; Leflore), Spavinaw (2.10 inches; Mayes) and Bengal (2.09 inches; Latimer). Numerous other sites reported more than an inch of rain. Lightning or high winds toppled a historic church steeple in McAlester (Pittsburg).
 
May 13, 1996
Isolated areas of Pittsburg county reported as much as 7.60 inches of rain that closed many roads and caused street flooding in Hartshorne.
 
May 14, 1998
Winds, not associated with any thunderstorm, at the Goodwell Mesonet site gusted to 65 miles per hour.
 
May 14, 1996
Thunderstorms produced baseball-sized hail at Bixby and a small tornado near Blair.
 
May 15, 1991
A tornado spawned from a storm near Laverne eventually grew to a width of nearly 1/2 mile. Three people were injured when the tornado struck a trailer home south of Laverne.
 
May 15, 1990
A devastating tornado in Stillwater destroyed 27 homes and caused $5 million in damage. Another tornado in Rogers County damaged 10 homes, but caused only 8 minor injuries. Tornadoes were also reported in Kingfisher, Creek, Mays, and Tulsa Counties. Widespread severe storms produced softball-sized hail near Canton Lake, tennis ball-sized hail in Hydro, and smaller hail in the Muskogee, Eufaula, and Wilburton areas.
 
May 17-21, 2001
On the 17th and the morning of the 18th, wide-spread incidents of hail and high winds were reported, including 73 miles per hour at both the Hobart (Kiowa) and Medicine Park (Comanche) Mesonet sites. Lightning ignited an oil field fire near Byng (Pontotoc). The Red Rock Mesonet site (Noble) recorded 5.24 inches of rain on the 18th. Tornadoes were reported near Reydon (Roger Mills), Erick (Beckham) and Altus (Jackson) on the 19th, accompanied by hail and high winds elsewhere. A tornado that struck Stigler (Haskell) on the 20th was one of 10 tornadoes reported in the state on that date. Other tornadoes were reported near Wetumka (Hughes), Dustin (Hughes), between Hanna and Stidham in McIntosh County, near Enterprise (Haskell), Pawhuska (Osage), Pryor (Mayes), Tupelo (Coal), Centrahoma (Coal) and near Spiro (LeFlore). Two-and-three-quarter inch hail was reported in Pontotoc and Atoka counties. Mesonet stations at Stigler (Haskell) and Goodwell (Texas) recorded peak winds of 92 and 75 miles per hour, respectively. Daisy (Atoka) and Spiro (LeFlore) each reported 5.26 inches of rain on the 21st.
 
May 19, 1990
Several hail-producing severe thunderstorms struck northeastern and central Oklahoma. Three-inch hail pounded central Oklahoma causing an estimated $70 million of property damage.
 
May 21, 1987
Yukon reported 2 inches of hail on the ground with some stones as big as tennis balls.
 
May 22, 1996
A system of thunderstorms in southwestern Oklahoma collapsed on the evening of the 22nd. This collapse led to a dry outflow that produced winds estimated as great as 105 miles per hour and led to a rare “heatburst” that drove night time temperatures in many areas up into the upper 90s and gave Chickasha an “overnight high” of 102 degrees. Extensive wind damage was reported in Lawton and the effects were felt from Hollis in the southwest to Norman.
 
May 22, 1989
Thunderstorms in Ponca City produced hail accumulations of 6 inches.
 
May 23, 2000
Altus Mesonet recorded a high temperature of 112 degrees, an all-time state record for May.
 
May 24, 1998
Very strong thunderstorms ripped across north central Oklahoma, producing baseball-sized hail and 4.57 inches of rain at Medford. A series of tornadoes touched down between Amorita and Tonkawa. The storms produced an F3 tornado in and around Salt Fork and Lamont. The Newkirk Mesonet site recorded a peak wind of 73 miles per hour.
 
May 25, 2000
Thunderstorms produced softball-sized hail west of Brinkman and the Oklahoma Mesonet recorded winds greater than 80 miles per hour at Goodwell and Velma.
 
May 26, 1991
A severe thunderstorm near Woodward produced three tornadoes and softball-sized hail. The storms were also accompanied by frequent lightening.
 
May 27, 2001
Mesonet wind reports included: 93 miles per hour at Ardmore (Carter), 86 miles per hour at Camargo (Dewey), 85 miles per hour at Washington (McClain), 83 miles per hour at Putnam (Dewey), 81 miles per hour at Kingfisher (Kingfisher), and 80 miles per hour at Beaver (Beaver). Downed power lines created electrical outages in the Oklahoma City metropolitan area, affecting more than 60,000 homes and businesses. One tornado was reported in Alfalfa County.
 
May 29, 2003
Temperatures soared into the triple digits as Oklahoma City reached 100 degrees for the first time since August 2001. Altus and Grandfield were 107 and 106 degrees, respectively.
 
May 29, 2001
Tornadoes were reported near Braman (Kay), Kiowa (Pittsburg) and Yanush (Latimer). Two weather-related deaths were reported: an elderly women died from a fall suffered when she slipped on the stairs of her storm cellar and a passenger on a motorcycle was struck and killed by a falling branch. Several areas around Grand Lake suffered power loss. Flooding was reported in Muskogee, Okmulgee, Wagoner and Tulsa counties. Hectorville Mesonet site (Okmulgee) reported 5.40 inches of rain.
 
May 30, 2001
Conventional observing stations reporting daily rainfall totals in excess of five inches included: Perkins (Payne), 5.96 inches; Haskell (Muskogee), 5.94 inches; Cushing (Payne), 5.23 inches; and Oktaha (Muskogee), 5.09 inches.
 
May 31, 2001
Clayton (Pushmataha) reported 5.15 inches of rainfall.Thanks to Howard Johnson, Associate State Climatologist for Service (Retired) and Gary McManus, Climatologist, for the daily facts!
 
Thanks to Howard Johnson, Associate State Climatologist for Service (Retired) and Gary McManus, Climatologist, for the daily facts!
 
   
Oklahoma Mesonet University of Oklahoma