January 10, 2014

While areas of North America have endured record polar temperatures this week, the Southern Hemisphere, where it is summer, is experiencing the opposite extreme–record high temperatures. Temperatures in some parts of the sparsely populated Pilbara region along Australia’s rugged northwest coast hit 122 °F (50 °C) yesterday. The Australian newspaper The Blaze reports that the heat is so severe that an estimated 100,000 bats have died, “littering the ground and alarming authorities who warn locals not to touch the animals for fear of infection.” Large numbers of parrots, kangaroos, and emus have been found dead in the parched terrain around Winton, Queensland, the chief executive of the Winton Shire Council told media outlets.

Southern South America is sizzling as well. In Brazil, zookeepers in Rio de Janeiro are giving their charges ice pops to keep them cool in the 120 °F (49 °C) heat. An extended heat wave in Argentina recently overloaded the electric grid, resulting in blackouts that have left thousands of households without electric power. In the Argentine capital of Buenos Aires, record high temperatures have left hundreds of fish dead in city park lakes.

Australians often flock to Bondi Beach in Sydney to celebrate the Christmas holiday, which falls during the summer in the Southern Hemisphere. (© Mike Stone, Alamy Images)

Australia’s most recent heat wave follows its hottest year on record. The country’s  Bureau of Meteorology reported that in 2013, temperatures were 2.16 degrees Fahrenheit (1.2 degrees Celsius) above the long-term average, making 2013 the warmest year since record keeping began in Australia in 1910. The world’s driest continent also had its hottest day, hottest month, hottest winter’s day, and hottest summer in 2013. The hotter-than-normal temperatures, which began late in 2012, were so extreme that the Bureau of Meteorology was forced to change its official weather forecasting map to include two new colors—deep purple and pink—to show areas with temperatures above 122 °F (50 °C).

Additional World Book articles:

• Bushfires in Australia
• Australia 2009 (a Back in Time article)
• Global warming 2012 (a Back in Time article)
• The Great Meltdown (a special report)
• Meltdown: Climate Change in the Arctic (a special report)

July 3, 2013

Weather extremes unprecedented in records kept since 1850 pummeled Earth during the decade of 2001-2010, the World Meteorological Organization (WMO) reported today. The decade was the warmest for both hemispheres and for both land and ocean surface temperatures. The year 2010 was the warmest ever recorded, with an average temperature estimated at 1 Fahrenheit degree (0.54 Celsius degree) above the long-term average during the 1961-1990 base period. More national temperature records were reported broken than in any previous decade.

Extreme heat waves, particularly in Europe in 2003 and in Russia in 2010, caused a record number of deaths. The record high temperatures were accompanied by the rapid melting of Arctic sea ice, Antarctic ice sheets, and Greenland glacier ice. As a result, global mean sea levels rose during the 2001-2010 decade by 1/8 inch (3 millimeters) per year–about double the average rise of 1/16 inch (1.6 millimeters) during the 20th century.

Scientists believe that higher ocean temperatures are generating hurricanes of greater severity. (AP/Wide World)

The authors of the report analyzed trends, both global and regional, and such extreme events as Hurricane Katrina, floods in Pakistan, and droughts in the Amazon, Australia and East Africa. They noted that the decade of 2001-2010 was also the second wettest since 1901 and that 2010 was the wettest year ever recorded. They attribute the unprecedented weather extremes mainly to greenhouse gases generated by human action.

Additional World Book articles:

• Global warming
• Australia 2008 (a Back in Time article)
• Australia 2009 (a Back in Time article)
• Australia 2010 (a Back in Time article)
• Europe 2003 (a Back in Time article)
• Russia 2010 (a Back in Time article)
• Twisted–More Terrible Storms (a special report)

January 18, 2013

Sydney, Australia, is experiencing its hottest day on record, with temperatures reaching 114.4 °F (45.8 °C). The previous recorded high in Sydney–113.5 °F (45.3 °C)–was in January 1939. The heat has caused extensive damage to Sydney’s urban railway lines, causing delays to much of the network. Prime Minister Julia Gillard has advised Australians to “take the appropriate precautions to stay safe and monitor information from local emergency services as they work to protect lives and property.”

A record high of 104 °F (40 °C) set on January 8 prompted the Australian Bureau of Meteorology to add two new colors to its temperature charts to extend their range to 129 °F (54 °C) from the previous cap of 122 °F (50 °C). David Jones, manager of climate monitoring prediction at the Bureau of Meteorology, declared last week that Australia was undergoing the “largest heat event in the country’s recorded history.”

According to public safety officials, four months of record-breaking temperatures combined with widespread drought conditions and high winds have created “catastrophic” fire conditions along the heavily populated eastern and southeastern coasts of the country. These areas include Australia’s three largest cities, Sydney, Melbourne, and Brisbane, as well as the capital, Canberra. A bushfire in Victoria state has left one man dead. He was found in his burnt-out vehicle outside the town of Seaton, which is 120 miles (200 kilometers) east of Melbourne. Firefighters continue to battle dozens of wildfires sparked by the intense heat in Victoria and New South Wales, and whole towns and sheep ranches are reportedly cut off  by fires and endangered. (A bushfire is an uncontrolled fire in bush areas, especially the Australian bush.) Very similar conditions on Feb. 7, 2009, came to be known as Black Saturday, during which wildfires in Victoria state left 173 people dead and caused $4.4 billion in damage.

Additional World Book articles:

• Celsius scale
• Fahrenheit scale
• Why Fires Need to Burn (a special report)
• Australia 2009 (a Back in Time article)

January 10, 2013

The year 2012 was the hottest on record for the contiguous United States, with an average temperature of 55.3 °F (12.9 °C), which eclipsed 1998, the previous record holder, the National Oceanic and Atmospheric Administration (NOAA) announced this week. Temperature variations between years are usually measured in just fractions of a degree; 2012, however, was 1 full degree Fahrenheit (0.56 Celsius degree) warmer than the previous record temperature, set in 1998. In fact, the entire range between the coldest year on record, which occurred in 1917, and the previous warmest year on record, 1998, was just 4.2 Fahrenheit (2.4 Celsius) degrees.

The average 2012 springtime temperature in the lower 48 states was so far above the 20th century average–5.2 Fahrenheit (2.9 Celsius) degrees–that it set a record for the largest temperature departure for any season on record. July 2012, with an average temperature that was 3.6 Fahrenheit (2 Celsius) degrees above average, was the hottest month ever recorded in the contiguous United States.

Shades of red on the map indicate temperatures up to 8 Fahrenheit degrees warmer than average. Shades of blue indicate temperatures up to 8 Fahrenheit degrees cooler than average. The darker the color, the larger the difference from average temperature. (NOAA Climate.gov)

According to an unofficial count maintained by the Weather Channel, 34,008 new daily high records were set at weather stations in the United States in 2012, compared with only 6,664 new daily record lows. Fully 61 percent of the nation was engulfed in drought in 2012. In addition, with 11 natural disasters that exceeded a $1-billion damage threshold, 2012 turned out to be the second-worst year on record on the Climate Extremes Index, surpassed, again, only by 1998.

“Climate change has had a role in this [record],” noted Jake Crouch, a climate scientist at NOAA’s National Climatic Data Center in Asheville, North Carolina. Crouch stated his belief that it is unlikely such a record would have occurred without the long-term warming trend caused in large part by emissions of greenhouse gases.

Additional World Book articles:

• Climate
• National Weather Service
• Weather
• Weather 1998 (a Back in Time article)

January 9, 2012

Temperatures in Australia topped 104 °F (40 °C) on January 8, and the mean national temperature climbed to the highest in history, breaking a record set just the day before, on January 7, reported the Australian Bureau of Meteorology. The new record prompted meteorologists at the bureau to take the extraordinary step of adding two new colors to its temperature charts to extend their range to 129 °F (54 °C) from the previous cap of 122 °F (50 °C).

“If you look at yesterday, at Australia as a whole, it was the hottest day in our records going back to 1911,” noted David Jones, manager of climate monitoring prediction at the Bureau of Meteorology. “From this national perspective, one might say this is the largest heat event in the country’s recorded history.”

According to public safety officials, four months of record-breaking temperatures combined over the past week with widespread drought conditions and high winds have created “catastrophic” fire conditions along the heavily populated eastern and southeastern coasts of the country. These areas include Australia’s three largest cities, Sydney, Melbourne, and Brisbane, as well as the capital, Canberra. Firefighters and emergency crews in the state of New South Wales are facing a highly dangerous situation battling 130 separate bushfires. (A bushfire is an uncontrolled fire in bush areas, especially the Australian bush.) Very similar conditions on Feb. 7, 2009, came to be known as Black Saturday, during which wildfires in Victoria state left 173 people dead and caused $4.4 billion in damage.

Additional World Book articles:

• Celsius scale
• Fahrenheit scale
• Why Fires Need to Burn (a special report)
• Australia 2009 (a Back in Time article)

July 11, 2012

The average temperature across the continental United States for the first six months of 2012 was the warmest on record, announced the National Oceanic and Atmospheric Administration on July 9. The 12-month period ending on June 30 was also the warmest on record in the 48 contiguous states. Record keeping was begun by the National Weather Service in 1895. The average temperature through June–57.4 °F (14.1 °C)–is 4.5 degrees higher than the long-term average for the same period. In Colorado, the average temperature in June was 6.4 degrees higher than the historical average.

High temperatures in the second half of June broke or tied records in 173 locations across the nation. The temperature hit 115 °F (46.1 °C) on June 26 in Red Willow, Nebraska, breaking the 114 °F (45.5 °C) record set in 1932. The temperature reached an all-time high of 118 °F (47.7 °C) on June 28 in Norton, Kansas.

High temperatures in June contributed to a record-warm first half of the year and the warmest 12-month period the United States has experienced since record keeping began in 1895. (National Oceanic and Atmospheric Administration)

The first six months of the year were also drier than usual, with total precipitation 1.62 inches (4.11 centimeters) below average. According to the Weather Service’s weekly Drought Monitor, 56 percent of the nation experienced drought conditions in June.

The unusually high temperatures and drought conditions created ideal conditions for wildfires. Wildfires burned across 1.3 million acres (526,000 hectares) in the western United States in June alone.

Additional World Book article:

• Weather
• The Forecast: Better Weather Prediction Ahead  (a special report)
• When the Rain Stops (a special report)
• Weather 1932 (a Back in Time article)

May 11, 2012

Average atmospheric temperatures in the United States for the period from April 2011 to May 2012 were the highest for any consecutive 12-month period in 117 years, the National Climatic Data Center (NCDC) has reported. Average running temperatures were 2.6 °F (1.45 °C) above those for the 1900′s and 0.1 °F (0.06 °C) above those for the second-warmest 12-month period–November 1999 to October 2000. All of the top-10 warmest 12-month periods in the United States have occurred since June 1999. The record-breaking period also included the warmest March, the third-warmest April, the second-hottest summer, and the fourth-warmest winter on record. Twenty-two states reported record warmth during this 12-month period. The NCDC, a part of the National Oceanic and Atmospheric Administration, maintains the official weather records for the continental United States (not including Alaska and Hawaii) dating back to 1895.

Higher-than-normal temperatures (shown in red) severely damaged crops and livestock in the lower Great Plains states in the summer of 2011 and triggered massive wildfires in the Southwest. (NASA's Earth Observatory)

Many U.S. cities also broke temperature records for the first four months of 2012, according to preliminary data from the NCDC. Among them were Atlanta; Bismarck, North Dakota; Boston; Chicago; Detroit; Indianapolis; Oklahoma City; New Orleans; St. Paul, Minnesota; and Tampa, Florida. Overall, a record 42 percent of the country experienced extreme weather, chiefly extreme heat, during this period.

NCDC scientists said the record-breaking warm weather over the continental United States in 2012 “is related to a jet stream pattern which has locked up cold air in the high latitudes and favored sprawling heat domes over the mid-section of the country which have meandered east and west at times.” They also reported “the intensity and persistence of the warmth compared to the past is very likely related to the elevated greenhouse concentrations in the atmosphere from human activities.”

Additional World Book articles:

• Climate
• Global warming
• The Great Meltdown (A Special Report)
• Global warming 2011 (A Back in Time article)
• Global warming 2010 (A Back in Time article)

April 10, 2012

March 2012 was the warmest March in the United States since record keeping began in 1895, the National Oceanic and Atmospheric Administration (NOAA) announced on April 9. The first quarter of 2012–January, February, and March–was the warmest ever recorded in the continental United States (not including Alaska and Hawaii). The average temperature was 42 °F (5.5 °C), 6 degrees Fahrenheit above the long-term average. The warm temperatures contributed to conditions favorable for severe thunderstorms and tornadoes. According to NOAA’s Storm Prediction Center, more than 220 tornadoes were reported in the United States in March.

A resident surveys the wreckage of a house blown off its foundation by a tornado. Most tornado damage is severe but localized. (AP Photo)

On March 2, for example, deadly storms blew across the Midwest and South, spawning dozens of tornadoes that left 40 people dead amid the rubble of destroyed buildings and overturned vehicles. The storms touched down in 9 states, killing 21 people in Kentucky, 13 in Indiana, 4 in Ohio, and 1 each in Alabama and Georgia. According to the National Weather Service, the four tornadoes that hit Kentucky with winds of up to 160 miles (358 kilometers) per hour were the worst in the region in 24 years. In Indiana, an EF-4 tornado–the second highest rating on the Enhanced Fujita  scale–slammed Henryville with winds of 175 miles (280 kilometers) per hour, then mowed over southeastern Indiana for more than 50 miles (80 kilometers). The March 2 storms resulted in the first billion-dollar disaster of 2012.

Additional World Book articles:

• Global warming
• Weather

March 16, 2012

Spring weather has come early to the United States, according to meteorologists at the National Oceanic and Atmospheric Administration (NOAA). On March 14, 400 locations around the United States reported record highs. Even the 68 °F (20 °C) temperature at Duluth, Minnesota, which was far below the 80 °F (27 °C) reported in Miami, Houston, and Chicago, was 35 Farhrenheit degrees (19 Centigrade degrees) above average.

Spring 2012 is following the fourth-warmest U.S. winter since record keeping began in 1895. Unseasonably warm temperatures have resulted in such welcome developments as lower natural gas heating costs for consumers, as well as concerns among farmers that spring frosts may damage crops that produce buds this early.

Because of the early arrival of spring in the United States, the famous cherry blossoms that tourists flock to the nation's capital to see are expected to bloom early. (Courtesy Dean Brown from Nancy Palmer)

The winter of 2012, which meteorologists define as the period from Dec. 1, 2011, to Feb. 29, 2012, brought no major snowstorms to the United States. Snow cover in early March, as photographed by NASA’s Terra Earth observing satellite, was much spottier and less thick than the snow cover recorded for the same time in 2011.

The less extensive snow cover, according to NOAA scientists, has lowered the risk of spring flooding. For the first time in four years, no area in the United States was expected to experience major spring flooding, according to an agency report released on March 15. At this time in 2011, half the country was at above-average risk of flooding.

According to meteorologists, the warm spring weather may be the result of two climate patterns in effect in 2012. One is a La Nina, during which cooler-than-normal water temperatures in the eastern Pacific Ocean produce warmer-than-normal temperatures and drier conditions in much of the United States. A strong La Nina has been in effect throughout 2011 and is just beginning to dissipate. Another weather pattern affecting U.S. climate is the Arctic Oscillation (AO). That phenomenon, in which changes in air pressure affect the circulation of warm and cold air masses in the upper atmosphere, has been bottling up cold Arctic air in regions around the North Pole.

Will the warm weather continue? NOAA forecasters indicate that temperatures for the rest of March, April, and May will probably be about one Fahrenheit degree (0.6 Centigrade degree) above normal. Nevertheless, one or two extreme temperature fluctuations during that period remain possible.

Additional World Book articles:

• Global warming
• Ocean (How the ocean moves)