May 2012 Climate Summary

For a printable version of the climate summary which includes more figures, data tables, and state summaries, click here. 

Temperature Summary

May 2012 was largely warm and dry across the High Plains Region. The largest temperature departures occurred in southern portions of the Region, where the departures from normal temperature ranged from 4.0-8.0 degrees F (2.2-4.4 degrees C) above normal. The only areas in the Region to have lower than normal temperatures were central and western North Dakota and pockets of Wyoming and South Dakota. Many locations across the Region were ranked in the top 10 warmest Mays on record. For instance, Topeka, Kansas had its 2nd warmest May on record with an average temperature of 71.4 degrees F (21.9 degrees C). The record of 72.7 degrees F (22.6 degrees C) was set back in 1962 (period of record 1887-2012).

Many locations set daily records as temperatures soared near the end of the month. Some locations even had their earliest 100 degrees F (37.8 degrees C) day on record. Scottsbluff, Nebraska set a daily record of 100 degrees F (37.8 degrees C) on May 22nd, absolutely crushing the old record of 91 degrees F (32.8 degrees C) set back in 1939 (period of record 1893-2012). Not only was this a new daily record, this was also the earliest 100 degrees F (37.8 degrees C) day on record in Scottsbluff. On average, temperatures there do not reach 100 degrees F (37.8 degrees C) until July 3rd. Prior to this new record, the earliest 100 degrees F (37.8 degrees C) day was May 28th (1934).

According to the National Agricultural Statistics Service, the earliest start to the wheat harvest in Kansas since records began in 1952 has occurred this year. By the end of the month, at least 4 percent of the wheat harvest was complete. The earliest harvest prior to this year occurred in 1962 when 1 percent of the crop had been harvested by June 2nd. The dry, hot, and windy weather in Nebraska led to low soil moisture which caused producers to turn on pivots to aid in crop germination. Although rain was a welcome sight to some, the tornadoes and hail that accompanied the storms led to crop damage which will require producers to replant in some areas of Nebraska.

This spring (March, April, and May) was a record breaker across the entire High Plains Region. Average temperatures were above normal at all locations in the Region and the largest temperature departures occurred in the east as areas of South Dakota, Nebraska, and Kansas had average temperatures which were over 8.0 degrees F (4.4 degrees C) above normal. Most locations set new records or were at least ranked in the top 5 warmest springs on record. Some of the impressive records include those set in Lincoln, Nebraska and Wichita, Kansas. Lincoln had an average temperature of 59.3 degrees F (15.2 degrees C) which was 8.5 degrees F (4.7 degrees C) above normal and beat its old record of 56.1 degrees F (13.4 degrees C), set in 1977, by 3.2 degrees F (1.8 degrees C) (period of record 1887-2012). Wichita had an average temperature of 64.4 degrees F (18.0 degrees C), which was 9.0 degrees F (5.0 degrees C) above normal and beat its old record of 59.9 degrees F (15.5 degrees C) by a whopping 4.5 degrees F (2.5 degrees C) (period of record 1888-2012).

Precipitation Summary

May 2012 was dry for much of the High Plains Region. A large area encompassing southern Wyoming, western and southern Nebraska, northern and western Kansas, and the east and west sides of Colorado had precipitation totals which were less than 50 percent of normal. In addition, many locations within that area received only 25 percent or less of normal precipitation and ranked in the top 10 driest Mays on record. Goodland, Kansas had its 2nd driest May on record with only 0.45 inches (11 mm) of precipitation, which was 13 percent of normal precipitation (period of record 1895-2012). The 1927 record held at 0.31 inches (8 mm). Snowpack in Colorado and Wyoming continued to decline. According to the Natural Resources Conservation Service, by the end of the month, the statewide snowpack was just 5 percent of average in Colorado and 22 percent of average in Wyoming. According to the Denver Post, the low snowpack has raised concerns about potential impacts on river recreation in Colorado.

Although the majority of the Region was drier than normal, a few areas had above normal precipitation totals including eastern South Dakota, northeastern Nebraska, south-central Colorado, and a few pockets of North Dakota and Wyoming. The highest precipitation amounts were located in eastern South Dakota where totals exceeded 200 percent of normal. Extremely heavy rain fell in eastern South Dakota during the May 5-6 timeframe. The 24-hour precipitation total, ending May 6th, for Madison 2 SE, South Dakota was 4.81 inches (122 mm)! This crushed the old daily record of 3.44 inches (87 mm) set back in 2007 and also set a new 1-day May precipitation record (period of record 1961-2012). The old 1-day precipitation total was 3.79 inches (96 mm), set on May 1, 1972. By the end of the month, this had become the wettest May on record for Madison 2 SE with a total of 9.97 inches (253 mm). The old record of 8.53 inches (217 mm) occurred in 1972. In addition, this also became the wettest month on record for Madison 2 SE, beating out the old record of 9.57 inches (243 mm) which occurred in June 1984.

Spring (March, April, and May) precipitation and snowfall totals were some of the lowest on record in the western part of the High Plains Region. A large area of the Region had precipitation totals which were 25-50 percent of normal including southern Wyoming, the panhandle of Nebraska, and western and northern Colorado. Some examples of the dryness include Cheyenne, Wyoming and Boulder, Colorado. Cheyenne had its 2nd driest spring on record with only 0.69 inches (18 mm) of liquid equivalent precipitation. This was not far off from the record 0.67 inches (17 mm) which was set in the spring of 1880 (period of record 1871-2012). In addition, Cheyenne had its least snowy spring on record with only 0.6 inches (2 cm) of snowfall. This beat the old record of 3.5 inches (9 cm) which occurred in 2007 (snowfall period of record 1883-2012). Similarly, Boulder, Colorado had its 3rd driest spring with 3.10 inches (79 mm) of precipitation. The record 2.21 inches (56 mm) which fell in 1925 was able to hold on (period of record 1893-2012). Boulder also had its least snowy spring on record with a mere 1.6 inches (4 cm) of snowfall. This easily beat the old record of 3.5 inches (9 cm) which fell in 1982 and was incredibly lower than the average spring snowfall, which in Boulder is 29.5 inches (75 cm).

Climate Outlook

ENSO-neutral conditions are present and these conditions are expected to continue through the summer. The temperature outlook indicates a higher probability of above normal temperatures for all of Colorado, the majority of Wyoming, all of Kansas except the far northeast corner, western and south-central Nebraska, and the far southwestern corner of South Dakota.  The precipitation outlook indicates a higher probability of below normal precipitation for northwest Wyoming. Equal chances of above, near, or below normal precipitation and temperature are predicted elsewhere in the Region. The seasonal outlooks combine the effects of long-term trends, soil moisture, and when applicable, the El Niño Southern Oscillation cycle (ENSO). More information about these forecasts can be found here.

Drought Watch

There were many changes again to the U.S. Drought Monitor this month. Improvements were made in eastern South Dakota and Nebraska as drought conditions were eliminated due to ample precipitation. Only small areas of abnormally dry conditions (D0) remained there. Moderate drought conditions (D1) were erased from western South Dakota and the majority of western North Dakota as well. Unfortunately, drought conditions elsewhere either emerged or worsened over the course of the month. D1 conditions in eastern North Dakota expanded towards the south. New D0 and patches of D1 have emerged across Kansas. D1 conditions also expanded further across southern Colorado and also across the panhandle of Nebraska and into southern Wyoming and northwestern Colorado. The big story this month was the development of extreme drought conditions (D3) in northwestern Colorado due to extremely low precipitation. According to the U.S. Seasonal Drought outlook released on May 17th, drought conditions were expected to improve in areas of North Dakota and the panhandle of Nebraska. Drought conditions in Colorado, southern Wyoming, and southwestern Kansas were expected to persist.