Oklahoma monthly climate summary, 07/2012

              Copyright © 2012 Board of Regents of the University of Oklahoma.
Oklahoma Monthly Climate Summary 1
Heat exploded across Oklahoma during July thanks to a rapidly intensifying drought and a persistent upper-level ridge of high pressure. The combination of dry soils, wilting vegetation and a brutal summer sun led to the sixth warmest July on record for the state. Those records date back to 1895. According to preliminary data from the Oklahoma Mesonet, the statewide average temperature finished at 85.9 degrees, 4.3 degrees above normal. July becomes the 23rd month out of the last 28 to finish warmer than normal, a persistent signal that began in April 2010. The first two months of summer were the ninth warmest on record at 3.2 degrees above normal. The drought’s impacts became more significant as the month progressed. The USDA rated the moisture levels of 96 percent of the state’s topsoils and subsoils as either “poor” or “very poor” in a report released on July 30. That report also rated 64 percent of the state’s pastures and rangelands as being in either “poor” or “very poor” condition. County-level USDA offices from across the state reported a rapid deterioration of crops and vegetation as well as diminishing stock ponds. The lush green growth of the state’s warm and wet early spring was transformed into abundant fuel for wildfires as it became dormant or dead. Many large fires were reported during the latter half of the month.
JULY 2012
Oklahoma Monthly Climate Summary
July 2012 Statewide Extremes
Description
Extreme
Station
Day
High Temperature
112ºF
Several
31
Low Temperature
57ºF
Camargo
12
High Precipitation
5.75 in.
Idabel
--
Low Precipitation
0.0 in.
Marshall, Spencer, Waurika
--
July 2012 Statewide Statistics
Temperature
Average
Depart.
Rank (1895-2012)
Month (July)
85.9ºF
4.3ºF
6th Warmest
Season-to-Date (Jun-July)
82.3ºF
3.2ºF
9th Warmest
Year-to-Date (Jan-July)
63.9ºF
4.8ºF
1st Warmest
Precipitation
Average
Depart.
Rank (1895-2012)
Month (July)
1.11 in.
-1.63 in.
15th Driest
Season-to-Date (Jun-July)
3.86 in.
-3.14 in.
13th Driest
Year-to-Date (Jan-July)
17.92 in.
-3.97 in.
34th Driest
Depart. = departure from 30-year normal
TEMPERATURE
The January-July statewide average of 63.9 degrees was easily the warmest on record for the first seven months of the year at 4.8 degrees above normal. The heat broke or tied four daily records during the month at Oklahoma City and twice at Tulsa, including that city’s all-time high minimum temperature. Tulsa’s temperature only dropped to 88 degrees on July 30, breaking the previous all-time record high minimum temperature of 87 degrees set on August 2, 2011, and July 16, 1980. The highest temperature recorded during the month was 112 degrees on July 31 at several locations. The century mark was reached at all 120 Mesonet stations on both July 29 and July 31.
JULY DAILY HIGHLIGHTS
JULY 1-5: The first day of July saw a few showers and storms in the Panhandle. Over a half of an inch fell in Goodwell. Showers the following day in the southeast provided similar totals. A weak mid-level disturbance produced some light rain on the third after midnight. The totals throughout the period were not significant. Temperatures throughout the first five days ranged from the mid-90s to triple-digits. Winds were strong from the south, gusting to 35 mph.
PRECIPITATION
The month was also the 15th driest July on record with a statewide average rainfall total of 1.11 inches, 1.63 inches below normal. The moisture deficit during July continued a dry streak that began in April and intensified during May, encompassing the bulk of Oklahoma’s primary rainy season. The May-July statewide average rainfall total of 5.99 inches fell 6.25 inches below normal and ranked as the third driest such period on record. Three of the 120 Oklahoma Mesonet stations – Marshall, Spencer and Waurika – recorded no rainfall for the month of July and 10 recorded less than a tenth of an inch. Idabel led the state with 5.75 inches. July 31 marked the 55th day since the Mesonet stations at both Norman and Watonga recorded more than a tenth of an inch of rain in a single calendar day.