Earth has its Warmest May and Warmest Year-to-Date Period on Record

May 2015 was Earth's warmest May since global record keeping began in 1880, said NOAA's National Centers for Environmental Information (NCEI) on Thursday. NASA rated May 2015 as the 2nd warmest May on record. May 2015's warmth makes the year-to-date period (January - May) the warmest such period on record, according to both NOAA and NASA, and it is likely that 2015 will be Earth's second consecutive warmest year on record. Five of the ten warmest months in recorded history have occurred in the past six months, according to NOAA:

NOAA's top ten warmest global monthly departures from average
1) 0.89°C, Mar 2015
1) 0.89°C, Feb 2015
3) 0.88°C, Jan 2007
4) 0.87°C, May 2015
4) 0.87°C, Feb 1998
6) 0.84°C, Dec 2014
6) 0.84°C, Mar 2010
8) 0.83°C, Nov 2013
9) 0.82°C, Apr 2010
10) 0.81°C, Jan 2015

Global ocean temperatures during May 2015 were the warmest on record, and global land temperatures were tied for warmest on record. Global satellite-measured temperatures in May 2015 for the lowest 8 km of the atmosphere were the 5th or 4th warmest in the 37-year record, according to the University of Alabama Huntsville (UAH) and Remote Sensing Systems, respectively.


Figure 1. Departure of temperature from average for May 2015, the warmest May for the globe since record keeping began in 1880. Record warmth occurred across most of Alaska, parts of tropical South America, much of southern Africa and The Middle East, and parts of northwestern Siberia. Only part of the central United States, far west central Australia, Iceland, and part of Far East Russia observed temperatures characterized as "cooler than average" for May. Image credit: National Centers for Environmental Information (NCEI) .


Figure 2. Departure of temperature from average for the globe for 12-month periods ending in May each year, starting in 1880 and ending in 2015. There is no evidence of a long term slow-down in global warming. Image credit: NOAA.

Deadliest weather disaster of May 2015: India's brutal heat wave
The deadliest weather-related disaster of May 2015 was an intense heat wave in India that killed approximately 2,500 people. According to statistics from EM-DAT, the International Disaster Database, the 2015 heat wave in India was their second deadliest heat wave and Earth's fifth deadliest heat wave ever recorded; the heat wave was also the planet's 11th deadliest weather-related disaster since 2000. Note that heat waves and droughts hold three of the top five spots on the list of deadliest disasters since 2000, suggesting that society is not prepared for the increase in the intensity of heat waves and droughts that is already occurring due to a warming climate:

Death Tolls From Earth's Deadliest Weather-Related Disasters Since 2000
1) Cyclone Nargis, Mayanmar, 2008: 138,366
2) Heat wave, Europe, 2003: 71,310
3) Heat wave, Russia, 2010: 55,736
4) Drought, Somalia, 2010 - 2011: 20,000
5) Typhoon Haiyan, Philippines, 2013: 7,354
6) Flood, India, 2013: 6,054
7) Cyclone Sidr, Bangladesh, 2007: 4,234
8) Heat wave, Europe, 2006: 3,418
9) Hurricane Jeanne, Haiti, 2004: 2,754
10) Flood, Haiti, 2004: 2,665
11) Heat wave, India, 2015: 2,500
12) Flood, Pakistan, 2010: 1,985
13) Typhoon Bopha, Philippines, 2012: 1,901
14) Hurricane Katrina, U.S., 2005: 1,833
15) Landslide, China, 2010: 1,765



Three billion-dollar weather disasters in May 2015
Three billion-dollar weather-related disasters hit the Earth last month, according to the May 2015 Catastrophe Report from insurance broker Aon Benfield: a severe weather outbreak and flooding on May 23 - 28 in the Central U.S. that caused at least $1 billion in damage; flooding in China that caused $1.15 billion in damage; and the on-going drought in California and neighboring states that now has a price tag of at least $3 billion.


Disaster 1. "Exceptional" drought--the most severe classification made--continued across California during the month of May. A study conducted by the UC Davis Center for Watershed Sciences on behalf of the California state government concluded that statewide economic losses from the drought will top $2.7 billion in 2015. Including damage from neighboring states--particularly Washington--the overall total losses will be at least $3.0 billion. In this photo from May 24, 2015, we see houseboats moored on a shrinking arm of California's Oroville Lake reservoir, which was at 52 percent of its usual level. Image credit: MARK RALSTON/AFP/Getty Images.


Disaster 2. A wave of severe thunderstorms, tornadoes, and torrential rains swept through the heart of the U.S. May 23 - 28, killing 32 people and causing over $1 billion in damage. The heaviest flooding and damage was in Texas and Oklahoma, which suffered their rainiest month in recorded history. In this photo, we see a severe thunderstorm with golfball-sized hail that pounded Wetmore, KS on May 25, 2015. Image credit: Wunderphotographer idzrvit.


Disaster 3. Flooding, landslides and hail from seasonal rains in southern China from May 18 - 22 killed at least 48 people and did $1.15 billion in damage in the provincial regions of Fujian, Jiangxi, Hunan, Guangdong, Guangxi, and Guizhou. An estimated 87,000 homes were damaged or destroyed, and more than 100,000 hectares (247,000 acres) of cropland were inundated. This picture taken on May 20, 2015 shows a rescuer with a life buoy in floodwaters during an intense rainstorm that killed 7 people in Xiamen, in eastern China's Fujian province. Image credit: STR/AFP/Getty Images.

Arctic sea ice falls to 3rd lowest May extent on record
Arctic sea ice extent during May 2015 was the 3rd lowest in the 36-year satellite record, according to the National Snow and Ice Data Center (NSIDC). By the end of May, sea ice extent had fallen to an all-time record low extent for the date, and continued to track at an extent between the lowest and 4th lowest on record during the first half of June. The near-record late May - early June retreat in sea ice was due to wind patterns favorable for sea ice loss combined with sunnier than usual weather in the Arctic.

Notable global heat and cold marks set for May 2015
Hottest temperature in the Northern Hemisphere: 49.8°C (121.6°F) at Larkana, Pakistan, May 21
Coldest temperature in the Northern Hemisphere: -44.8°C (-48.6°F) at Summit GEO, Greenland, May 2
Hottest temperature in the Southern Hemisphere: 38.8°C (101.8°F) at Skukuza, South Africa, May 16
Coldest temperature in the Southern Hemisphere: -81.2°C (-114.2°F) at Concordia, Antarctica, May 28

Major stations that set (not tied) new all-time heat or cold records in May 2015
Truong Sa, Spratly Islands (Vietnam), max. 35.9°C, May 16
Khammam (India), max. 47.6°C, May 23
Nainital (India), max. 31.0°C, May 26
Mussoorie (India), max. 36.0°C, May 26
Con Cuong (Vietnam), max. 42.7°C, May 30 (Tied all-time national high set at Tuong Duong on May 12, 1966)
Quy Hop (Vietnam), max. 42.6°C, May 30

* On May 14 Palau tied its all-time hottest temperature on record with 34.4°C at Babelthuap Airport, a value which was set in few occasions before both at the airport and at Nekken Forestry.



New all-time national and territorial heat records set or tied in 2015
As of June 15, 2015, eight nations or territories have tied or set all-time records for their hottest temperature in recorded history thus far in 2015, and one (Israel) has set an all-time cold temperature record. For comparison, only two nations or territories set all-time heat records in 2014, and nine did in 2013. The most all-time national heat records held by any year is nineteen in 2010. Most nations do not maintain official databases of extreme temperature records, so the national temperature records reported here are in many cases not official. I use as my source for international weather records researcher Maximiliano Herrera, one of the world's top climatologists, who maintains a comprehensive list of extreme temperature records for every nation in the world on his website. If you reproduce this list of extremes, please cite Maximiliano Herrera as the primary source of the weather records. Wunderground's weather historian Christopher C. Burt maintains a database of these national heat and cold records for 235 nations and territories on wunderground.com's extremes page. Here are the all-time national or territorial heat and cold records set so far in 2015:

Vietnam tied its national heat record of 42.7°C (108.9.0°F) at Con Cuong on May 30.
Palau tied its national heat record of 34.4°C (94.0°F) at Koror Airport on May 14.
Venezuela set a new national heat record of 43.6°C (109.9°F) at Coro on May 29. Previous record: 42.0°C (107.6°F) at Machiques, Zulia State in February 1983.
Laos tied its national heat record of 42.0°C (107.6°F) at Thakhek on May 20.
Ghana set a new national heat record of 43.3°C (109.9°F) at Navrongo on May 10. This is the third time this year Ghana has tied or set a new all-time heat record. Previous records: 43.1°C (109.6°F), set the previous day, on May 9, and 43.0°C (109.4°F) on February 12.
Cocos Islands (Australian territory) tied their all-time heat record with 32.8°C (91.0°F) on May 8.
Equatorial Guinea set a new national heat record of 35.5°C (95.9°F) at Bata on March 17. Previous record: 35.3°C (95.5°F) at Malabo in February 1957.
Wallis and Futuna Territory (France) set a new territorial heat record with 35.5°C (95.9°F) on January 19 at Futuna Airport.

Israel set a new national cold record of -14.2°C (6.4°F) at Merom Golan on January 10.

Special Mention: Antarctica set a new heat record for its mainland of 17.5°C (63.5°F) at Esperanza Base on March 24. Previous record: 17.4°C (63.3°F) at Marambio Base, set the previous day. The World Meteorological Organization (WMO) has appointed a committee to study this event and determine if this represents an official record for the continent. Note that this is a record for mainland Antarctica, not a territorial or continental record. The all-time maximum record for the continent and territory of Antarctica is 19.8°C (67.6°F) on January 30, 1982, in Signy Island, South Orkney, an island group located about 450 miles northeast of the tip of the Antarctic Peninsula, the northernmost portion of mainland Antarctica. Geologically, the South Orkney are on the Antarctic plate, and politically, they are part of Antarctica. This record was improperly listed as a territorial record for Antarctica in last month's global summary.

Mr. Herrera originally listed Samoa as tying its national heat record with 36.5°C (97.7°F) on January 20 at Asau, but a subsequent review of the record revealed possible issues with the measurement equipment, so this record is dubious.

Have a great weekend, everyone!

Jeff Masters