1. Highest Temperature

A record high temperature of 115°F occurred multiple times in multiple locations across the state: Buffalo (7/9/2009), Erick and Hollis (6/26/2011), Wilburton and Wister (8/3/2011), and Kingfisher (8/1/2012).

115°F

Email: operator@mesonet.orgPhone: 405.325.2541

120 David L. Boren Blvd., Suite 2900Norman, OK 73072

Top 20 Extreme Weather Events in Mesonet History Started in 1994 in response to a recognized need for a statewide monitoring network, the Oklahoma Mesonet has become the gold standard for statewide weather and climate networks. With 120 network stations measuring a variety of environmental conditions across Oklahoma 24/7, the Mesonet has observed some incredible things over the last 20 years. Take a look at what the state with the most severe and unpredictable weather has experienced;

2. Highest Heat Index On August 9, 1999, Calvin, Oklahoma (site now retired) experienced a heat index of 125°F. That month, triple-digit temperatures were present somewhere in the state every day. At the time, this was the 19th warmest August in Oklahoma since 1892.

3. Lowest Temperature On February 10, 2011, Nowata, Oklahoma experienced a low temperature of -31°F. One day prior to this, a massive winter storm concluded in the state. Reports of 6-12 inches of snow were widespread across the state and up to 21 inches of snow were reported in localized areas in the northeast. Blizzard conditions paralyzed travel and buried some locations in the north under 5-10 feet of snow.

125°F

-31°F

4. Lowest Wind Chill On February 10, 2011, Medford, Oklahoma experienced a lowest wind chill of -47°F. This extremely rare wind chill was accompanied by state-wide havoc as areas of Oklahoma experienced temperatures as low as -31°F and up to 27 inches of snowfall in within 24 hours.

5. Warmest Low Temp August 2012 took off with a record-breaking temperature of 115°F in Kingfisher. Trailing closely behind were portions of north central Oklahoma at 114°F. The majority of Oklahoma stayed near and above 110°F for their maximum temperature, keeping minimum temperatures high. On August 2, 2012, Stillwater, Oklahoma experienced a warmest low temperature of 89°F. The minimum temperatures allowed for little relief across the state.

6. Coldest High Temp A massive winter storm bringing sleet and freezing rain quickly turned to snow overnight and continued through the day. Winds gusted over 50 mph over much of the state, combining with the snow to create true blizzard conditions. Frigid temperatures added to the storms impacts. Wind chill temperatures plummeted to less than -20°F, keeping the high temperatures in the teens. On February 2, 2011, Kenton, Oklahoma experienced a coldest high temperature of 4°F.

-47°F

89°F

4°F

7. Longest Stretch of Consecutive Hours Below Freezing The longest stretch of consecutive hours below freezing occurred in Vinita, Oklahoma from December 23, 2000 to January 4, 2001. During this period 282 consecutive hours (11 Days, 18 hours) passed before the temperature rose above 32°F.

8. 101 Days with High Temperatures above 100°F In 2011, Grandfield set a state record by experiencing 101 days with temperatures above 100°F. 2011 brought with it the hottest summer in Oklahoma history.

9. Hottest Summer in Oklahoma The hottest summer in Oklahoma history occurred during June through August in 2011 with an average high temperature of 100.5°F.

282 Hours

Grandfield in 2011

2011(Avg. High 100.5°F)

10. 50 Days with Consecutive High Temps Above 100°F For 50 consecutive days, the sites of Walters, Tipton, Hollis, Grandfield, and Altus recorded temperatures above 100°F. This occurred from June 22 to August 10, 2011.

11. Greatest 7 Day Temperature Change On February 10, 2011, a cooling trend ensued and a passing band of snow and sleet came through Oklahoma. After several days of frigid temperatures, a warming trend brought with it climbing high temperatures and in seven days the temperature at Nowata went from -31°F to 79°F from February 10 to February 17, 2011, a change of 110°F.

12. Greatest 1 hour Temperature Change On March 8, 2002, the temperature at May Ranch dropped from 74°F to 34°F in a single hour making that the greatest 1 hour temperature change ever recorded by the Mesonet.

Walters, Tipton, Hollis, Grandfield, and Altus

110°F

40°F

13. Greatest 1 hour Rainfall On June 14, 1996, Cheyenne, Oklahoma experienced an unprecedented 6.47 inches of rain in a single hour. Caused by a slow moving, localized thunderstorm, Cheyenne and other nearby stations recorded large amounts of rainfall between June 12th and June 17th, but the state still remained below average for June precipitation that year.

14. Highest Annual Rain In 2009, Broken Bow, Oklahoma experience the highest annual rainfall ever recorded by the Mesonet with 76.61 inches of rainfall.

15. Lowest Annual Rain In 2011, the site of Hooker, Oklahoma experienced the lowest annual rainfall of 6.23 inches.

6.47”

76.61”

6.23”

16. Highest 1 Day Rainfall The stormiest period of 2009 began in late April with multiple storms occurring between April 25th and 30th. On April 29th, three tornadoes touched down, but the big story was the rainfall in southern Oklahoma. The Mesonet station at Burneyville recorded 12.42 inches of rainfall on the 29th and 30th, breaking several records. Other stations in the area had upwards of 7 inches during the same event.

17. Windiest Day Across Oklahoma On February 24, 2007, storms from the Texas Panhandle quickly moved into western Oklahoma and eastward overnight. As the dry line and cold front passed through the state, severe non-thunderstorm winds gusted to over 60 mph. Blowing dust and power outages resulted. It would become the windiest day across the entire state as the average measured wind gust of every Mesonet site was 52.2 mph.

18. Mesonet Site Struck by Lightning the Most Times Mesonet sites are located in open fields and are generally taller than their immediate surroundings, making the sites prone to lightning strikes. The Clayton, Oklahoma site holds the Mesonet record of 6 lightning strikes. In both 1996 and 1999, the site was struck in April and again in May. Sites now have lightning rods and deeply buried ground cables, which significantly reduce the number of sensors destroyed by lightning strikes.

12.42”

Avg. Gust of 52.2 mph

Clayton, 6 times

19. Highest Wind Gust

On May 24, 2011, tornadic supercells raced across western, central, and eastern Oklahoma. The day included several violent EF-4 tornadoes and an EF-5 twister that struck the Oklahoma Mesonet site northwest of El Reno. The Mesonet station registered a maximum wind gust of 151 mph as well as a large and sudden pressure drop associated with the tornado. It caused significant and catastrophic damage along its path - killing nine people.

151 mph

20. Mesonet Sites Destroyed by Tornadoes A round of storms fired up in northwest Texas on the afternoon of November 7th, 2011 and moved into southwestern Oklahoma. Those storms became tornadic and the first tornado was a monster EF-4, the first of its kind to occur in November, which struck the OSU Agronomy Research Station near Tipton. The station was demolished, as was the Oklahoma Mesonet site at Tipton. As these tornadic storms moved northeast another tornado destroyed the Fort Cobb Mesonet site.

120 David L. Boren Blvd., Suite 2900 Norman, OK 73072 phone: 405.325.2541 fax: 405.325.2550Email: operator@mesonet.org Copyright © 1994-2014 Board of Regents of the University of Oklahoma. All Rights Reserved.

Tipton and Fort Cobb