monthly climate summary

A pleasantly cool final day and scattered heavy rains during the month’s final week were too little and too late, and May entered the record books as one of the warmest and driest in state history. According to data from the Oklahoma Mesonet, the statewide average temperature finished at 72.2 degrees, 4.3 degrees above normal. That ranks May as the fifth warmest on record. Statewide average records date back to 1895. That heat, combined with the state’s warmest March and tenth warmest April, propelled the spring season to the warmest on record at 65.1 degrees, 6 degrees above normal.

Golf clubs replaced parkas as the outdoor accessory of choice this winter, and Oklahoma’s kids can only dream of missed school days filled with sledding and snowball fights. The mildness of this winter – the 11th warmest on record at nearly 3 degrees above normal – stands in stark contrast to the cold, snowy experiences of the previous two years. The winter of 2009-10 was the state’s seventh coldest on record at more than 4 degrees below normal. Statewide average records date back to 1895. Oklahoma City and Tulsa both recorded approximately 23 inches of snow that cool season.

September brought Oklahomans relief from the heat and October did its part with a bit of drought relief. The drought conditions remain quite severe across the state despite the rain, however. The statewide average rainfall total was 2.89 inches, about a half of an inch below normal and the 52nd wettest October since 1895. The month was also a bit on the warm side at more than a half a degree above normal. The statewide average temperature of 61.9 degrees ranks as the 53rd warmest October on record.

While little relief from drought was found in September, the reprieve from the intense summer heat was nearly instantaneous. After three summer-like days to begin the month, fall weather kicked into high gear and temperatures plummeted. The hottest summer in Oklahoma history soon gave way to the 30th coolest September since records began in 1895. The statewide average temperature for the month was 70.9 degrees according to preliminary data from the Oklahoma Mesonet, 1.6 degrees below normal. Unfortunately, similarly good news did not arrive for most of drought-stricken Oklahoma.

To get a sense of the state’s legendary heat waves of its past, Oklahoma’s youngest generation would normally turn to the stories of parents, grandparents or great-grandparents. Tales of those summers from the 1930s, 1950s and even 1980 seemed as dated as rotary phones or changing the television channel by hand. They will no longer need to ask older generations about harsh summers, however. They now have their own stories to tell, and theirs will be from the hottest of them all – the summer of 2011.

Fueled by exceptional drought and a seemingly impenetrable heat-dome, July roared through Oklahoma’s legendary heat waves of the past to become the state’s hottest calendar month on record. According to data from the Oklahoma Mesonet, the July statewide average temperature finished 7.5 degrees above normal at 89.1 degrees, smashing the previous record of 88.1 degrees set back in July 1954. Statewide averages date back to 1895. The news was equally grim on the rainfall side of the ledger.

The meager amount of rain that managed to fall on Oklahoma during June was no match for the extreme heat and wind that was so prevalent for much of the month. The statewide average rainfall total for June was 1.17 inches, more than 3 inches below normal and the fourth driest June on record dating back to 1895. Southwestern Oklahoma suffered through its driest June on record with an average of 0.52 inches. Add heat to the equation and you have the ingredients for drought intensification. That is exactly what occurred during what became the second warmest June on record.

Even though severe weather only struck on a few days during May, those instances gave the month more than its money’s worth. The most violent weather occurred on May 24 when several long-track violent tornadoes tore their way through Oklahoma from west to east. While the exact details of the twisters are still being discovered, their 10 confirmed fatalities are unfortunately all too certain. Those casualties make the month the deadliest due to tornadoes in Oklahoma since May 1999.

Warm and dry weather grabbed the headlines as the record-setting extremes of February gave way to a downright dull March. Data from the Oklahoma Mesonet ranked the month as the eighth driest and 31st warmest March since records began in 1895. Severe weather was scarce, although a few reports of large hail and high winds accompanied the few thunderstorms that did occur. Elevated fire risk was common during the month, a result of the dry and windy conditions.

In a state accustomed to extreme weather, February was a bit startling to even the most seasoned veteran of Mother Nature’s whimsy. The roller coaster ride began on the month’s first day with a crippling blizzard and ended on its last with tornado warnings. The month was peppered with records, including the state’s all-time lowest minimum temperature and greatest 24-hour snowfall total. Those extremes occurred amidst the larger backdrop of an intensifying drought across the western two-thirds of the state.