National Overview - December 2012
Maps and Graphics
Temperature and Precipitation Ranks
U.S. Percentage Areas
Note: GHCN-M Data Notice
An omission in processing a correction algorithm led to some small errors on the Global Historical Climatology Network-Monthly dataset (GHCN-M v3.2.0). This led to small errors in the reported land surface temperatures in the October, November, December and Annual U.S. and global climate reports. On February 14, 2013, NCDC fixed this error in its software, included an additional improvement (described below), and implemented both changes as GHCN-M version 3.2.1. With this update to GHCN-M, the Merged Land and Ocean Surface Temperature dataset also is subsequently revised as MLOST version 3.5.3.
The net result of this new version of GHCN-M reveals very small changes in temperature and ranks. The 2012 U.S. temperature is 0.01°F higher than reported in early January, but still remains approximately 1.0°F warmer than the next warmest year, and approximately 3.25°F warmer than the 20th century average. The U.S. annual time series from version 3.2.1 is almost identical to the series from version 3.2.0 and that the 1895-2012 annual temperature trend remains 0.13°F/decade. The trend for certain calendar months changed more than others (discussed below). For the globe, ranks of individual years changed in some instances by a few positions, but global land temperature trends changed no more than 0.01°C/century for any month since 1880.
NCDC uses two correction processes to remove inhomogeneities associated with factors unrelated to climate such as changes in observer practices, instrumentation, and changes in station location and environment that have occurred through time. The first correction for time of observation changes in the United States was inadvertently disabled during late 2012. That algorithm provides for a physically based correction for observing time changes based on station history information. NCDC also routinely runs a .pairwise correction. algorithm that addresses such issues, but in an indirect manner. It successfully corrected for many of the time of observation issues, which minimized the effect of this processing omission.
The version 3.2.1 release also includes the use of updated data to improve quality control and correction processes of other U.S. stations and neighboring stations in Canada and Mexico.
Compared to analyses released in January 2013, the trend for certain calendar months has changed more than others. This effect is related to the seasonal nature of the reintroduced time-of-observation correction. Trends in U.S. winter temperature are higher while trends in summer temperatures are lower. For the globe, ranks of individual years changed in some instances by a few positions, but global temperature trends changed no more than 0.01°C/century for any month since 1880.
More complete information about this issue is available at this supplemental page.
NCDC will not update the static reports from October through December 2012 and the 2012 U.S and Global annual reports, but will use the current dataset (GHCN-M v. 3.2.1 and MLOST v. 3.5.3) for the January 2013 report and other comparisons to previous months and years.
- Climate Highlights — December
- The average contiguous U.S. temperature for December was 36.4°F, 3.4°F above the 20th century long-term average, and the 10th warmest December on record.
- Warmer-than-average conditions were present for much of the U.S. east of the Rockies. Twenty states had monthly temperatures that ranked among the ten warmest on record. Near-average conditions were present for the Northern Plains and much of the West. The Pacific Northwest was slightly warmer than average.
- The nationally-average precipitation for December was 2.74 inches, which was 0.51 inch above average and the 20th wettest December on record.
- Wetter-than-average conditions were present for the interior West, where Nevada and Utah both had a top ten wet month. The Northeast and parts of the Ohio Valley had a wetter-than-average December. Maine, New York, Ohio, and Pennsylvania also had a top ten wet month. The Southern Plains were drier than average during December.
- According to the January 1st, 2013 U.S. Drought Monitor report, 61.1 percent of the contiguous U.S. was experiencing moderate-to-exceptional drought, smaller than the 62.7 percent at the end of November. Drought conditions improved in parts of the Southeast, Northwest, and northern California and Nevada. Drought conditions worsened in parts of the Southwest and Southern Plains.
- Several large snow storms traversed the nation during December causing the monthly average snow cover extent to be above average. According to data from the Rutgers Global Snow Lab, the monthly average snow extent of 1.3 million square miles (3.2 million square km) was 100,800 square miles (261,100 square km) above the 1981-2010 average and the 14th largest monthly snow cover extent in the 47-year period of record.
Alaska Temperature and Precipitation:
- Alaska had its 18th coolest December since records began in 1918, with a temperature 5.9°F (3.3°C) below the 1971–2000 average.
- Alaska had its 14th coolest October-December since records began in 1918, with a temperature 3.4°F (1.9°C) below the 1971–2000 average.
- Alaska had its 11th coolest January-December since records began in 1918, with a temperature 2.3°F (1.3°C) below the 1971–2000 average.
- Alaska had its 31st driest December since records began in 1918, with an anomaly that was 18.0 percent below the 1971–2000 average.
- Alaska had its 24th driest October-December since records began in 1918, with an anomaly that was 14.4 percent below the 1971–2000 average.
- Alaska had its 35th wettest January-December since records began in 1918, with an anomaly that was 9.2 percent above the 1971–2000 average.
For additional details about recent temperatures and precipitation across the U.S., see the Regional Highlights section below and visit the Climate Summary page. For information on local temperature and precipitation records during the month, please visit NCDC's Records page. For details and graphics on weather events across the U.S. and the globe please visit NCDC's Global Hazards page.
These regional summaries were provided by the six Regional Climate Centers and reflect conditions in their respective regions. These six regions differ spatially from the nine climatic regions of the National Climatic Data Center.
- Northeast Region: (Information provided by the Northeast Regional Climate Center)
- After a cooler than normal November, December returned to the 2012 trend of above normal temperatures. In fact, with an average temperature of 33.6 degrees F (0.9 degrees C), 4.8 degrees F (2.7 degrees C) above normal, it was the 7th warmest December on record in the Northeast. All states were warmer than normal with all but one placing December 2012 as one their top 15 warmest. Delaware had their warmest December on record averaging 7.0 degrees F (3.9 degrees C) above normal. Departures for the rest of the states ranged from +5.7 degrees F (3.2 degrees C) in Vermont, their 6th warmest, to +3.2 degrees F (1.8 degrees C) in Maine, their 21st warmest. With an average temperature of 50.2 degrees F (10.1 degrees C), 2.7 degrees F (1.5 degrees C) above normal, preliminary data indicates the Northeast region had its warmest year on record. Preliminary data also indicates that eight of twelve of the Northeast states had their warmest year on record while the other four states had one of their top 5 warmest. Departures among the states ranged from +2.0 degrees F (1.1 degrees C) in West Virginia to +3.1 degrees F (1.7 degrees C) in Delaware.
- On the heels of one of the driest months on record, December turned out to be wetter than normal. With 5.27 inches (133.86 mm) of precipitation (151 percent of normal), it was the 9th wettest December in 118 years in the Northeast. All states reported wetter than normal conditions, with December in nine of twelve states ranked within the 2nd to 23rd wettest. Departures among the states ranged from 103 percent of normal in Connecticut and Maryland to 170 percent of normal in Pennsylvania. Despite a wet end to the year, the Northeast’s annual precipitation total of 42.78 inches (1086.61 mm) was only 96 percent of normal. Delaware, even after being poured on by Hurricane Sandy in October, was the driest of the states. The state was down 11.33 inches (287.78 mm) of precipitation, making it the 6th driest year since 1895. Of the dry states, departures ranged from 75 percent of normal in Delaware to 99 percent of normal in Pennsylvania. Maine was the only state to report above average annual precipitation at 110 percent of normal, their 28th wettest.
- At the beginning of the month, warm air ahead of an advancing cold front helped several cities set new maximum temperature records. Highs on the 3rd and 4th reached up to 72 degrees F (22.2 degrees C) in the Northeast. A series of storms moved through the region from the 16th to the 19th. Nearly 2 feet (61.0 cm) of snow fell in northern Maine while eastern Pennsylvania had ¼ inch (6.35 mm) hail and parts of Massachusetts had up to ¾ inch (19.05 mm) of ice accumulation. Another storm moved through from the 20th through the 22nd. Two to three inches (50.8 to 76.2 mm) of rain fell in New Jersey, Pennsylvania and Delaware causing flooding and road closures. A Nor’easter on the 26th created difficulties for holiday travelers. The storm dropped over 20 inches (50.8 cm) of snow on parts of upstate New York and Maine. Sections of Interstate 84 and the Taconic State Parkway in New York were closed for several hours due to accidents. Heavy rain, over 3 inches (76.2 mm), and high winds with gusts to 70 mph (31 m/s) affected coastal areas. About 7,000 customers on Long Island lost power. A quick, hard-hitting snowstorm moved through on the 29th bringing another 12 to 20 inches (30.5 to 50.8 cm) to parts of the Northeast. The storm caused a 20-car pileup on Interstate 93 in New Hampshire and a regional jet to skid into a snow bank in Albany, NY.
- For more information, please go to the Northeast Regional Climate Center Home Page.
- Midwest Region: (Information provided by the Midwest Regional Climate Center)
- December temperatures ranged from near normal in northwest Minnesota to as much as 7 degrees F (4 C) above normal in Illinois and Indiana. The first two-thirds of the month were well above normal with the warmest days on the 3rd and 4th recording hundreds of record high temperatures across the Midwest. Cooler temperatures in the final week of the month were not enough to drag the monthly values back down to normal. Six of the nine Midwest states (Illinois, Indiana, Kentucky, Michigan, Missouri, and Ohio) ranked among the ten warmest dating back to 1895 but the region as a whole fell just outside the top ten.
- Despite the warm temperatures, December had multiple significant snows affect parts of the region. Heavy snows on the 9th and 10th brought up to 13 inches (33 cm) of snow to southern Minnesota. Blizzard conditions extended from Iowa to northern Michigan on the 19th and 20th dropping up to 15 inches (38 cm) of snow in parts of southern Wisconsin. Two storms followed similar paths from southeast Missouri to Lake Erie in the last week of December. The first storm brought blizzard conditions and together they dropped more than 10 inches (25 cm) of snow along the 4-state path. December precipitation totals ranged from less than half normal in northwest Minnesota and western Missouri to more than twice normal in southwest Minnesota and southeast Ohio. Statewide Ohio precipitation of 4.77 inches (121 mm) ranked as the 4th wettest December since 1895.
- Annual temperatures set records across the Midwest in 2012 based on records that date back to 1895. The region as a whole set a new record of 52.1 degrees F (11.2 C) breaking the 1931 record of 51.9 F (11.1 C). Missouri set a new statewide record of 58.5 F (14.7 C) topping the 1938 record of 57.6 F (14.2 C) while statewide records were tied in Illinois (1921) and Ohio (1998). Each of the six remaining states in the region ranked as the second or third warmest in the last 118 years. Each state had at least one major city, with records dating back prior to 1900, set or tie their annual temperature record: Illinois (Chicago), Indiana (Indianapolis and South Bend), Iowa (Des Moines), Kentucky (Louisville), Michigan (Detroit, Grand Rapids, Lansing, and Muskegon), Minnesota (Minneapolis-St. Paul), Missouri (Columbia and St. Louis), Ohio (Cleveland and Columbus), and Wisconsin (Green Bay, Madison, and Milwaukee).
- In 2012, the Midwest ranked as the 12th driest calendar year since 1895. Missouri (7th), Illinois (10th), Indiana (11th), and Iowa (11th) all ranked among the driest 10 percent of years and Kentucky and Michigan ranked among the driest 25 percent of years. Drought conditions were widespread in 2012. Drought expanded from 20 percent or less of the region than in the first five months of 2012 to more than 70 percent in July before dropping to around 55 percent by the end of the year. Areas in extreme drought topped 10 percent in July and climbed to more than a third of the region in August before dropping back below 10 percent in November. Drought conditions were most severe in the western third of the Midwest at the end of the year.
- For details on the weather and climate events of the Midwest, see the weekly summaries in the Midwest Climate Watch page.
- Southeast Region: (Information provided by the Southeast Regional Climate Center)
- Monthly average temperatures for December were above normal across the Southeast region. The greatest departures were found across the Carolinas and Virginia, as well as parts of Alabama and Georgia where monthly temperatures were between 5 and 7 degrees F (2.8 to 3.9 degrees C) above normal, while monthly temperatures were between 1 and 3 degrees F (0.5 and 1.6 degrees C) above normal across much of the Florida Peninsula, Puerto Rico, and the U.S. Virgin Islands. The warmest weather occurred during the first half of the month, with temperatures exceeding 70 degrees F (21.1 degrees C) as far north as northern Virginia from the 3rd to the 5th of the month. Temperatures reached 80 degrees F (26.7 degrees C) across eastern sections of Georgia in advance of a cold front from the 10th to the 12th of the month. Overnight temperatures were also warm during this period, with over 150 daily high minimum temperature records tied or broken across the Southeast. The passage of two strong cyclones brought cooler weather to the region during the final two weeks of the month. Subfreezing temperatures were reported as far south as Fort Myers, FL on the 23rd of the month, while maximum temperatures failed to reach 60 degrees F (15.6 degrees C) across parts of central Florida between the 27th and 30th of the month.
- Precipitation was variable across the Southeast region in December. Monthly totals were between 100 and 200 percent of normal across northern and central parts of Alabama, Georgia, and South Carolina, as well as across portions of North Carolina and the Florida Peninsula. Tuscaloosa, AL recorded 7.61 inches (193.3 mm) of precipitation for the month, which was nearly 3 inches (76.2 mm) above normal, while Atlanta, GA recorded 5.93 inches (150.6 mm) for the month, or more than 2 inches (50.8 mm) above normal. Much of this precipitation was connected with the passage of several strong frontal boundaries, particularly over the Christmas holiday. Newberry, SC, located to the northwest of Columbia, recorded 4.2 inches (106.7 mm) of precipitation on the 25th of the month, which set a monthly record 24-hour rainfall total (period of record: 1893-2012). In contrast, the driest locations were found across South Florida, where monthly rainfall totals were less than 1 inch (25.4 mm), or about 25 percent of normal. Precipitation in December was also variable across Puerto Rico, with above normal rainfall across the southern and western slopes and below normal rainfall across much of the interior and eastern portions of the island. Monthly precipitation was generally below normal across the U.S. Virgin Islands. The storm system that brought heavy rain across southern parts of the region over the Christmas holiday also contributed between 2 and 5 inches (50.8 and 127 mm) of snowfall across northern and western sections of Virginia and the higher elevations of western North Carolina. An additional 3 to 4 inches (76.2 and 101.6 mm) of snow was reported across the mountains of North Carolina and Virginia on the 21st of the month, while trace amounts of snow were reported across northern Alabama in the wake of a departing cyclone on the 29th of the month.
- There were 118 reports of severe weather across the Southeast in December, including 22 confirmed tornadoes. Two tornadoes touched down near Edgewater, FL in Volusia County on the 10th of the month. The strongest, an EF-1, caused major damage to as many as 45 homes and either snapped or uprooted over 100 trees. Two minor injuries were reported. Three tornadoes were confirmed across central Georgia in Telfair and Wheeler Counties on the 17th of the month, two of which were rated EF-1. Most of the damage was minor. On the 19th of the month, an EF-1 tornado tracked across Mobile, AL during the early morning hours. Numerous trees were snapped or blown down and large sections of roofing were blown off of several homes and businesses. On the 25th of the month, a total of 15 tornadoes were confirmed across central and southern Alabama, making it one of the largest Christmas Day outbreaks on record in the Southeast. Five of these tornadoes were rated EF-2 and resulted in extensive damage to trees, electrical poles, and numerous structures, including collapsed brick walls and cracked cement foundations. Numerous mobile homes were destroyed when the anchors holding them down were ripped from the ground. In some instances, the resulting debris was blown several hundred yards into nearby neighborhoods causing damage to other homes and structures. In one case, two occupants remained inside their home and sustained major injuries. In Mobile, AL, significant damage was reported at Murphy High School where several windows were blown out and some automobiles were flipped onto their sides. In addition, on the 26th of the month, an EF-1 tornado was confirmed near Beaufort, NC in Carteret County.
- Drought conditions continued to persist across the Southeast in December, as roughly 50 percent of the region was experiencing at least moderate drought (D1 and greater), according to the U.S. Drought Monitor by the end of the month. Areas of severe drought (D2) expanded across northern sections of South Carolina and parts of southwestern North Carolina, while the lack of rainfall across south Florida contributed to the re-emergence of abnormally dry (D0) conditions by the end of December. The dry weather across South Florida forced some citrus farmers to begin irrigating their groves, while warm temperatures aided in the growth of winter vegetables and the harvesting of some early winter crops. Farmers were also beginning to assess whether the subfreezing temperatures experienced towards the end of the month damaged any of their crops. In Georgia, all boat ramps on Lake Lanier were closed indefinitely on the 13th of the month due to low lake levels. However, beneficial rains across North Georgia helped raise the lake level nearly 18 inches (0.5 m) over the last two weeks of the month.
- For the second straight year, mean annual temperatures in 2012 were exceptionally warm across a large portion of the Southeast region. Several locations recorded their warmest (or tied their warmest) year, including Atlanta, GA, Columbus, GA, Columbia, SC, Norfolk, VA, Richmond, VA, and Washington D.C. Several other locations recorded one of their top 5 warmest years on record, including San Juan, PR, Tampa, FL, Fort Myers, FL, Tallahassee, FL, Montgomery, AL, Birmingham, AL, Huntsville, AL, Charleston, SC, Greenville-Spartanburg, SC, Greensboro, NC, Raleigh-Durham, NC, Cape Hatteras, NC, and Roanoke, VA. In terms of precipitation, it was the fourth driest year on record in Macon, GA and Columbus, GA, with preliminary annual totals of 32.41 and 35.21 inches (823.2 and 894.3 mm), respectively. In contrast, it was the second wettest year on record in Miami, FL with 86.94 inches (2208.3 mm), just 2.4 inches (61 mm) short of the record set in 1959.
- For more information, please go to the Southeast Regional Climate Center Home Page.
- High Plains Region: (Information provided by the High Plains Regional Climate Center)
- December 2012 average temperatures were within 2.0 degrees F (1.1 degrees C) of normal for most of the High Plains Region. Warmer areas included the eastern halves of Nebraska and Kansas, as well as central Wyoming, southern South Dakota, and the panhandle of Nebraska. Monthly average temperatures were generally 2.0-4.0 degrees F (1.1-2.2 degrees C) above normal in those areas, with a few areas ranging from 4.0-8.0 degrees F (2.2-4.4 degrees C) above normal. These temperatures were not record breaking. Cooler areas of the Region included northern North Dakota and south-central Colorado where average temperatures were 2.0-6.0 degrees F (1.1-3.3 degrees C) below normal. Although these temperatures were not low enough to break records, there were some locations that squeezed their way into the top 10 list. Alamosa, Colorado had its 10th coolest December with an average temperature of 11.6 degrees F (-11.3 degrees C), which was 6.3 degrees F (3.5 degrees C) below normal. The record of 5.1 degrees F (-14.9 degrees C) was set in 1991 (period of record 1906-2012). Even though Decem¬ber temperatures were below normal, 2012 ended as one of the warmest years on record in Alamosa. With an aver¬age temperature of 43.2 degrees F (6.2 degrees C), Alamosa had its 7th warmest year on record. The warmest year occurred in 1934 with an average temperature of 44.5 degrees F (6.9 degrees C).
- There were several storm systems that passed through the High Plains Region this month bringing much needed precipitation. Areas that received above normal precipitation included western portions of Wyoming and Colorado, a swath from eastern Colorado into northern Kansas and up through eastern Nebraska, and also eastern South Dakota. These areas generally received at least 150 percent of normal precipitation and localized areas received upwards of 400 percent of normal precipitation. The most significant storm systems to affect the Region occurred December 8-9, December 19-20, and December 31. The December 8-9 blizzard affected eastern South Dakota bringing localized heavy snow of up to 8.0-14.0 inches (20.0-36.0 cm) and high winds of 40-55 mph (64-89 km/h). This blizzard closed portions of I-29 and I-90. The December 19-20 blizzard brought heavy snow and high winds to much of Nebraska and northern Kansas. This blizzard caused many challenges to travelers as white out conditions closed many roads throughout both states and portions of I-80 in Nebraska. Finally, a New Year’s Eve winter storm blanketed Kansas with snow, the heaviest of which fell in the western part of the state with 6.0-10.0 inches (15-25 cm). Although there was above normal precipitation in many areas of the Region this month, it was not enough to improve the ongoing drought. The highlighted station this month was Grand Island, Nebraska which received 9.5 inches (24 cm) of snow and 1.66 inches (42 mm) of liquid equivalent precipitation. This precipitation amount ranked as the 13th wettest December on record (period of record 1895-2012). What was interesting about December’s precipitation total was that it was the highest precipitation total in one month since May. Although there were many areas which received above normal precipitation, there were also large areas of the Region which did not receive much precipitation this month, including a large area of southeastern Kansas, eastern North Dakota, and eastern Wyoming. These areas received less than 50 percent of normal precipitation. Mean¬while, much of southeastern Kansas received less than 25 percent of normal precipitation.
- According to the U.S. Drought Monitor, widespread drought conditions continued. Although much of the Region received rain and snow over the past month, this precipitation was only enough to stave off further deterioration of the drought. Overall, about 93 percent of the Region was still in moderate (D1) to exceptional (D4) drought. This was down slightly from the end of last month when 94 percent of the Region was in D1-D4. There were slight improvements in west-central North Dakota where a small section of abnormally dry conditions (D0) were erased and in southwestern Wyoming where a small section of extreme drought (D3) was downgraded to severe drought (D2). Drought conditions worsened slightly in Colorado and other areas of Wyoming. In Wyoming, D3 filled in the central part of the state and a small section of D4 developed in the southwest. In Colorado, D2 expanded in the north, and D3 and D4 conditions expanded slightly in the south. According to the U.S. Seasonal Drought Outlook released January 1st, drought conditions were expected to improve in North Dakota and far northwestern Wyoming. Drought was expected to persist elsewhere through March 2013.
- For more information, please go to the High Plains Regional Climate Center Home Page.
- Southern Region: (Information provided by the Southern Regional Climate Center)
- December was a much warmer month than normal over the entire Southern Region. Most stations averaged approximately 4 to 8 degrees F (2.22 to 4.44 degrees C) above normal. Temperatures in northern Texas, western Oklahoma and southern Louisiana typically averaged between 2 to 4 degrees F (1.11 to 2.22 degrees C) above normal. The highest anomalies were observed in northern Tennessee, where stations averaged between 6 to 8 degrees F (3.33 to 4.44 degrees C) above normal. All six states reported warmer than normal temperatures for the month. The statewide average temperatures for December are as follows: Arkansas reported 46.00 degrees F (7.78 degrees C), Louisiana reported 55.00 degrees F (12.78 degrees C), Mississippi reported 51.40 degrees F (10.78 degrees C), Oklahoma reported 41.80 degrees F (5.44 degrees C), Tennessee reported 45.30 degrees F (7.39 degrees C), and Texas reported 51.00 degrees F (10.56 degrees C). For Tennessee, it was the ninth warmest December on record (1895-2012), while Texas experienced its eleventh warmest on record (1895-2012). The remaining state rankings are as follows: Arkansas with its thirteenth warmest on record (1895-2012), Mississippi with its fourteenth warmest on record (1895-2012), Louisiana with its eighteenth warmest on record (1895-2012), and Oklahoma with its twenty-seventh warmest on record (1895-2012). Two states in the Southern Region also reported 2012 as its warmest year on record (1895-2012). These states are Oklahoma and Texas. Oklahoma's annual temperature average was 62.99 degrees F (17.22 degrees C), while in Texas, the state annual average temperature was 67.48 degrees F (19.71 degrees C). Arkansas reported its second warmest year on record (1895-2012) with an annual temperature average of 63.39 degrees F (17.44 degrees C).
- December was a drier than normal month for the western half of the Southern Region, while the eastern half experienced a wetter than normal month. The wettest portions of the region were observed in southern Mississippi, where precipitation totals averaged between 150-200 percent of normal. Conversely, much of southern and eastern Texas reported less than half the expected precipitation for the month. This was also the case for much of central Oklahoma. For Oklahoma, it was the thirty-second driest December on record (1895-2012), with a state monthly precipitation total of only 0.93 inches (23.62 mm). Texas experienced its twenty-fourth driest December on record (1895-2012) with a state precipitation total of 1.00 inches (25.40 mm). In contrast, Mississippi averaged 7.05 inches (179.10 mm), which was their twenty-seventh wettest December on record (1895-2012). Conditions were also wet across much of Louisiana. The state averaged 6.32 inches (160.50 mm), and it was their twenty-fifth wettest December (1895-2012). Other state average precipitation totals were as follows: Arkansas with 3.79 inches (96.27 mm), and Tennessee with 5.71 inches (145.00 mm). Ranks for both states fell in the middle two quartiles.
- Because much of the drought in the Southern Region is confined to Texas, Arkansas and Oklahoma, where precipitation was below average for the month, drought conditions remained relatively unchanged. There is a slightly larger area of extreme and severe drought in central Texas. In addition, the heavy rains in Louisiana helped remove drought conditions in the west central parishes. Some improvement also occurred in western Tennessee.
- Several tornadoes were reported on Christmas day. The outbreak spanned from southeastern Texas, across southern Louisiana and into southern Mississippi. In Louisiana, one person was reported injured in Rapides Parish. In Mississippi, several tornado injuries were reported. One person was injured in Wilkinson County, four people were injured in Forrest County, while seven were injured in Lawrence County.
- With state-wide reservoir storage in a declining trend, new water usage restrictions are in place in Austin, Corpus Christi, and several places in north central Texas. Other places are developing new plans for water conservation and storage. The North Texas and Upper Trinity water districts have seen significant declines in reservoir storage in recent months, with the latter planning on adding new lakes to its draw pool to increase total supply storage. Older plans are being further developed, such as the San Angelo plan to develop piping to the Hickory Aquifer, which is expected to see completion by September, 2014. Above average temperatures and low short-term rainfall are also driving concerns over potential wildfires, as evidenced by Bastrop's requesting an additional $7 million for fire response and grassland fires causing strain on some fire response teams (Information provided by the Texas Office of State Climatology).
- Several frontal passages resulted in strong winds and storms, causing damage in multiple events. Power outages were numerous, with over 60,000 and 70,000 in two separate events in Houston, with an additional 42,000 in Dallas and 4,900 in Austin from the latter event. A system late in the month brought snow and power outages to North Texas and Longview for Christmas, to the tune of 8,000 people without power, and tornadoes in Houston and Beaumont though with much less damage. Minor reports from wind and fog-driven traffic and landscaping damage were common as well in other parts of the state (Information provided by the Texas Office of State Climatology).
- Dryland crops in central Texas continue to struggle with concerns that winter wheat will not have significant yields. Farmers in the Panhandle are feeling the same concerns, though slightly higher precipitation accumulations are buoying their crops for the time being. Farmers all over the state are concerned about their fiscal future, as the 2008 farm bill allocating $300 billion in farm subsidies expired this year and progress on a new bill has been slow; suggested cuts to the bill between 20 to 30 billion dollars over 10 years is another cause for concern (Information provided by the Texas Office of State Climatology).
- For more information, please go to the Southern Regional Climate Center Home Page.
- Western Region: (Information provided by the Western Regional Climate Center)
- Much of the West saw a continuation of the above normal temperatures that have dominated this calendar year. Positive anomalies were seen throughout the month until the final week, when clear skies, persistent snow cover, and inversions produced cold temperatures that moderated the monthly average to near-normal values at many valley and basin locations. Precipitation was abundant throughout much of the West as an active pattern in the North Pacific brought a series of storms and moderate to heavy precipitation.
- Following a warm November, the Inland Northwest continued to be anomalously warm in December, with temperatures 3-6 F (1-3 C) above normal. Temperatures for the 2012 calendar year as a whole were above average for this area, especially throughout Montana. Billings saw its warmest year in a 78-year record with an average annual temperature of 51 F (10.5 C), and Missoula recorded its 4th warmest year at 45.3 F (7.4 C). To the south, Riverton, Wyoming saw its second warmest year since records began in 1940 at 48.7 F (9.3 C). In California’s Central Valley, Fresno tied for the 7th warmest December on record, which helped to seal 2012 as the warmest calendar year at an average temperature of 66.7 F (19.3 C). Records in Fresno began in 1948. In the desert Southwest, Tucson, Arizona had only a slightly warmer than average December, but still clinched the title of warmest calendar year in an 82-year record at an average 71.4 F (21.9 C). Phoenix, Arizona recorded its 2nd warmest year with an average annual temperature of 76.7 F (24.8 C). In contrast, central Alaska continued to follow a trend of cooler than normal temperatures that have persisted through the fall. Fairbanks was 13.2 F (7.3 C) cooler than normal this month at an average -17.3 F (-27.4 C), the 14th coldest December in a 63-year record. As Arctic sea ice extent increases after September’s all time low, the positive temperature anomalies present along Alaska’s North Slope throughout summer and fall finally gave way to cooler than normal December averages.
- A heavy precipitation event that began in the last week of November in the Northwest carried over into the first few days of December. Eight-day precipitation totals for November 28-December 5 exceeded 20 in (508 mm) at Honeydew and Brandy Creek in Northern California. Over 9 in (229 mm) of precipitation was recorded at several other northern California locations, and minor flooding occurred along creeks and rivers. Just before the Christmas holiday, another series of storms brought heavy precipitation to the Pacific Coast and Intermountain West. Storm totals for isolated locations in Northern California exceeded 10 in (254 mm) of rainfall, and locations along the Sierra Nevada crest received over 5 ft (152.4 cm) of snowfall. Another weaker shot of snowfall over the last few days of the month brought Sierra Nevada snowpack to nearly 140% of normal by December 31. In contrast, on the same date last year, the Sierra snowpack stood at 14-28% of normal. These storms also brought 15.8 in (40.1 cm) of snow to Elko, in eastern Nevada, making for the 8th snowiest December there since records began in 1888 with a total snowfall of 22.1 in (56.1cm). The Pacific Northwest received above normal precipitation in December as well, sealing several top-ten wettest year titles for 2012. Seattle-Tacoma Airport in Washington saw its 7th wettest year in a 65-year record with 48.26 in (1225 mm), 130% of normal. In eastern Washington, Spokane recorded its 12th wettest year in a record that began in 1881. In western Oregon, Medford saw its 7th wettest year on record and 146% of normal annual precipitation. Further inland, though wet conditions prevailed for December, 2012 as a whole was a dry. In Billings, Montana, 2012 was driest in a 78-year record at only 7.13 in (181 mm) of precipitation, 52% of normal. Persistent dry conditions led to an extended fire season in Montana that burned over 1 million acres in 2012. Wyoming also saw a dry 2012 with locations throughout the state recording top 10 driest years. In the Pacific, dry conditions continued in Hawaii. Honolulu received only 0.01 in (0.25 mm) rainfall this month, the location’s driest December in a record that began in 1949. Precipitation during the last three months has been below 50% of normal throughout the state with the exception of the west side of Kauai and Hilo on the windward side of the Big Island.
- December (all month): Fern Lake Fire, Rocky Mountain National Park, Colorado: The Fern Lake fire began on October 9 and was in inaccessible terrain until winds over 70 mph (112 kph) November 30-December 1 doubled the size of the fire and forced evacuations of outlying areas of Estes Park, Colorado. On December 8 and 9, cold temperatures forced firefighters off the fire. The fire is only 88% contained. At year’s end, the number of fires in the United States in 2012 was well below the 10-year average, while the acreage burned ranked third amongst the last 10 years.
- December 24: Sierra Avalanches: A rain event followed by over 3 ft (91.4 cm) of snow December 22-24 in the Sierra created unstable snow packs. Several avalanches occurred both in the backcountry and at Lake Tahoe area resorts. Two people were killed and two injured in avalanches at ski resorts on the 24th.
- December 13-14: King Tide Flooding in Coastal California: Astronomical high tides combined with a large swell and moderate precipitation caused minor flooding in low-lying coastal areas of California. Damages were minimal.
- For more information, please go to the Western Regional Climate Center Home Page.
See NCDC's Monthly Records web-page for weather and climate records for the most recent month. For additional national, regional, and statewide data and graphics from 1895-present, for any period, please visit the Climate at a Glance page.
PLEASE NOTE: All of the temperature and precipitation ranks and values are based on preliminary data. The ranks will change when the final data are processed, but will not be replaced on these pages. Graphics based on final data are provided on the Temperature and Precipitation Maps page and the Climate at a Glance page as they become available.