May 2020: Earth’s Warmest May on Record

June 12, 2020, 5:18 PM EDT

Above: People crossing a broken flooded road in the Satkhira district of southwest Bangladesh on June 6, 2020, in the aftermath of Cyclone Amphan. Thousands of shrimp enclosures were washed away, while numerous thatched houses, trees, electricity and telephone poles, dykes and croplands were damaged and many villages were submerged by Amphan's storm surge. (Piyas Biswas/SOPA Images/LightRocket via Getty Images)

May 2020 was the planet's warmest May since record keeping began in 1880, said NOAA's National Centers for Environmental Information (NCEI) and NASA on Friday, June 12. NOAA rated May as tied with 2016 for warmest May on record, while NASA put May 2020 ahead of May 2016 by 0.06°C. Minor differences in rankings often occur between NOAA and NASA, due to the different techniques they use to handle data-sparse regions such as the Arctic.

The year-to-date period of January-May ranks as the second warmest such period on record, just 0.06°C behind the record set in 2016. According to NCEI's outlook for annual temperature, the year 2020 has more than a 99.9% chance to rank among the five warmest years on record, and a 49% chance of being the warmest year on record. If so, each of the past seven years (including 2020) will have been among the seven warmest years on record.

NASA classified May 2020 as having the 17th-highest monthly temperature departure from average for any month in the 1,684-month record, dating back to 1880: 1.02°C (1.84°F) above the 20th century average. All five months of 2020 rank in the top 20 for warmest of any month on record.

Global temperature records are more likely to be set during the peak of the solar cycle--and during strong El Niño events, due to the extra heat the tropical Pacific Ocean gives up to the atmosphere. The remarkable warmth of 2020 has come in the absence of an El Niño event and during the minimum of one of the weakest 11-year solar cycles in the past century, underscoring the dominant role human-caused global warming has in heating our planet.

Global ocean temperatures during May 2020 were the second warmest on record, and global land temperatures were the warmest on record. Global satellite-measured temperatures in May 2020 for the lowest 8 km of the atmosphere were the second warmest or warmest in the 42-year record, according to the University of Alabama Huntsville (UAH) and Remote Sensing Systems, respectively.

Three billion-dollar weather disasters in May 2020; thirteen for the year

Three billion-dollar weather-related disasters hit the Earth last month, according to the May 2020 Catastrophe Report from insurance broker Aon:

1. Nine severe weather events hit China in May, affecting 26 provinces and killing 20 people. Damage was estimated at $1.1 billion.

2. After peaking as a category 5 storm with 160 mph winds, a weakening Cyclone Amphan made landfall near the India/Bangladesh border as a category 2 storm with 100 mph winds. The cyclone triggered evacuations of 4.2 million people, and destroyed or damaged 2.8 million homes in India and 225,000 in Bangladesh. Amphan killed 133 people and left damages estimated at $15 billion, making it the most-costly Indian Ocean tropical cyclone in history. The large number of evacuations likely led to an increase in spread of Covid-19 in both India and Bangladesh.

3. An extensive severe weather outbreak hit Texas and the Southeast U.S. on May 27 - 28. Supercells produced swaths of large and significant hail, notably near San Antonio, with hail up to 2.5 inches in diameter. Damaging winds hit the Houston metro area, with a gust of 65 mph (105 kph) reported in Harris County. Damage was expected to top $1 billion.

Through the end of May, Earth had seen 13 billion-dollar weather disasters for the year. The Australian wildfires span the boundary between 2019 and 2020, though, and may end up being classified as a 2019 disaster rather than a 2020 disaster. Three May severe weather outbreaks—two in the U.S., and one in Australia—had over $900 million in damage, and may end up being billion-dollar disasters once final damage tallies are available later in the year.

Here is the 2020 list of billion-dollar weather disasters, according to Aon:

1. Cyclone Amphan, India and Bangladesh, 5/15 – 5/22, $15 billion, 133 killed

2. Severe Weather, Midwest, Plains, Southeast, and Mid-Atlantic U.S., 4/10 – 4/14, $3.1 billion, 38 killed

3. Windstorm Ciara, Western & Central Europe, 2/9 – 2/10, $2.3 billion, 14 killed

4. Wildfires and Heatwave, Australia, 11/8 – 1/17, $2+ billion, 34 killed

5. Severe Weather/Nashville Tornado, Central and Eastern U.S., 3/2 – 3/5, $2.0 billion, 25 killed

6. Severe Weather, Midwest, Plains, Southeast, and Mid-Atlantic U.S., 4/6 – 4/9, $1.9 billion, 0 killed

7. Severe Weather, Central and Eastern U.S., 3/27 – 3/30, $1.8 billion, 0 killed

8. Severe Weather, Australia, 1/18 – 1/20, $1.42 billion, 0 killed

9. Severe Weather, Central and Eastern U.S., 2/3 – 2/8, $1.25 billion, 5 killed

10. Severe Weather, Central and Eastern U.S., 1/10 – 1/12, $1.2 billion, 12 killed

11. Flooding, Iran, 2/24 – 4/30, $1.2 billion, 23 killed

12. Severe Weather, Plains, Southeast, and Mid-Atlantic U.S., 4/21 – 4/24, $1.1 billion, 7 killed

13. Severe Weather, Plains and Southeast U.S., 5/27 – 5/28, $1.0 billion, 0 killed

The deadliest weather event of 2020 so far has been the ongoing flooding in East Africa from the “Long Rain” season, which runs from March through May. Over 500 people have died in the floods. Kenya and Rwanda have been the hardest-hit, with 237 and 209 deaths, respectively, through the end of May.

Neutral El Niño conditions reign

NOAA’s June 11 monthly discussion of the state of the El Niño/Southern Oscillation (ENSO) stated that neutral ENSO conditions existed, with neither an El Niño nor a La Niña event in progress. Over the past month, sea surface temperatures (SSTs) in the benchmark Niño3.4 region of the eastern tropical Pacific (5°N-5°S, 170°W-120°W) cooled, falling to 0.3°C below-average. This is short of the 0.5°C below-average threshold needed to be considered La Niña conditions, though.

Forecasters at NOAA and the International Research Institute for Climate and Society (IRI) are calling for a roughly 60% chance of neutral conditions continuing through the Northern Hemisphere summer. They put the odds of a La Niña forming during the autumn or winter at about 45 – 50%, about the same odds as neutral conditions for the period. For the August-September-October peak of the hurricane season, they put the odds of El Niño at 6%, and the odds of a La Niña event at 46% (a rise from the 30% chance given a month ago). Atlantic hurricane seasons tend to be much more active during La Niña conditions than during El Niño conditions, due to weaker upper-level winds creating lower amounts of wind shear. During La Niña events, the U.S. East Coast from Georgia to Maine sees a significant increase in landfall frequency compared to ENSO-neutral years, according to a 2007 paper.

Arctic sea ice: fourth lowest May extent on record

Arctic sea ice extent during May 2020 was the fourth lowest in the 42-year satellite record, according to the National Snow and Ice Data Center (NSIDC). The record low for May occurred in 2016. Antarctic sea ice extent in May 2020 was below the 1981 – 2010 average by a modest amount.

Notable global heat and cold marks for May 2020

Hottest temperature in the Northern Hemisphere: 50.6°C (123.1°F) at Nawabshah, Pakistan, 27 May

Coldest temperature in the Northern Hemisphere: -33.2°C (-27.8°F) at Summit, Greenland, 1 May

Hottest temperature in the Southern Hemisphere: 40.2°C (104.4°F) at Kleinberg, Namibia, 5 May

Coldest temperature in the Southern Hemisphere: -76.6°C (-105.9F) at Concordia, Antarctica, 18 May

Highest 2020 average temperature to date (1 Jan-31 May) worldwide: 33.3°C (91.9°F) at Yelimane, Mali

Highest 2020 average temperature to date (1 Jan-31 May) in the Southern Hemisphere: 30.8°C (87.4°F) at Wyndham AP and Marble Bar, Australia

(Courtesy of Maximiliano Herrera.)

Major weather stations that set (not tied) new all-time heat or cold records in May 2020

Among global stations with a period of record of at least 40 years, 9 set (not just tied) a new all-time heat record in May, and 0 set all-time cold records:

Danxian (China) max. 41.1°C (106.0°F), 7 May

Luodian (China) max. 41.2°C (106.2°F), 8 May

Paphos (Cyprus) max. 42.5°C (108.5°F), 17 May

Lao Cai (Vietnam) max. 41.8°C (107.2), 21 May

Hai Duong (Vietnam) max. 39.6°C (103.3°F), 21 May

Hung Yen (Vietnam) max. 40.5°C (104.9°F), 21 May

Montreal Trudeau (Canada) max. 36.6°C (98.9°F), 27 May

Ste Anne de Bellevue (Canada) max. 36.1°C (97.0°F), 27 May

Mount Mansfield (Vermont, U.S.) max. 29.4°C (84.9°F), 27 May

Four all-time national/territorial heat record set or tied in 2020

As of June 12, four nations had set an all-time national heat record in 2020:

Colombia: 42.6°C (108.9°F) at Jerusalen, 19 February (tie)

Ghana: 44.0°C (111.2°F) at Navrongo, 6 May

Cuba: 39.2°C (102.6°F) at Palo Seco, 10 April; broken again on 11 April with 39.3°C (102.7°F) at Veguitas, and again on 12 April with 39.7°C (103.5°F) at Veguitas

Mayotte, France dependency: 36.4°C (97.5°F) at Trevani, 14 April

No all-time national cold records have been set thus far in 2020.

(Courtesy of Maximiliano Herrera.)

Fifty-four monthly national/territorial heat record beaten or tied in 2020 as of June 13

In addition to the four all-time national heat records, 54 other national monthly heat records have been set thus far in 2020, for a total of 58 national monthly heat records:

January (13): Norway, South Korea, Angola, Congo Brazzaville, Dominica, Mexico, Indonesia, Guinea Bissau, Gambia, Sao Tome and Principe, Cuba, British Indian Ocean Territory, Singapore

February (10): Spain, Antarctica, Azerbaijan, Costa Rica, The Bahamas, Switzerland, Maldives, Gambia, Russia, Seychelles

March (7): Paraguay, Cabo Verde, Mozambique, Seychelles, United States, Thailand, Northern Marianas Islands

April (13): Paraguay, Niger, St. Barthelemey, Honduras, Guernsey, Haiti, Congo Brazzaville, Kyrgyzstan, Mongolia, China, Saba, Northern Marianas Islands, U.S. Virgin Islands

May (10): Niger, Greece, Saba, Cyprus, Solomon Islands, Turkey, Haiti, Kazakhstan, Chile, Uzbekistan

June (1): Maldives

One monthly national cold record has been beaten or tied in 2020:

April: St. Eustatius

(Courtesy of Maximiliano Herrera.)

Hemispherical and continental temperature records in 2020

Highest minimum temperature ever recorded the Northern Hemisphere in January: 29.1°C (84.4°F) at Bonriki, Kiribati, 17 January.

Highest maximum temperature ever recorded in North America in January: 42.0°C (107.6°F) at Vicente Guerrero, Mexico, 21 January.

Highest temperature ever recorded in continental Antarctica and highest February temperature ever recorded in Antarctica plus the surrounding islands: 18.4°C (65.1°F) at Base Esperanza, 6 February.

Highest minimum temperature ever recorded in February in Antarctica: 7.6°C (45.7°F) at Base Marambio, 9 February.

Highest minimum temperature ever recorded in March in the Northern Hemisphere: 32.0°C (89.6°F) at Yelimane, Mali on 23 February.

Highest minimum temperature ever recorded in May the Southern Hemisphere: 31.1°C (88.0°F) at Argyle, Australia on 2 April.

Highest minimum temperature ever recorded in May in Europe: 30.1°C (86.2°F) at Emponas, Greece on 17 May.

Highest minimum temperature ever recorded in May in North America: 35.0°C (95.0°F) at Death Valley, California (U.S.), 28 May.

(Courtesy of Maximiliano Herrera.)

My new home at Yale Climate Connections

Since my two homes for blogging are both permanently shutting down this month—the Scientific American blog network, which shut down on June 8, and the Cat6 blog, where Bob Henson will make his final post on June 19—I have established a new blogging home. On June 10, I began writing as a volunteer for yaleclimateconnections.org, a nonpartisan, multimedia service providing daily broadcast radio programming and original web-based reporting, commentary, and analysis on the issue of climate change. My blog is called “Eye on the Storm”, and all of my posts to Yale Climate Connections can be found there. Bob Henson will also be a regular contributor to Yale Climate Connections.

My first post analyzed three papers on the value of wetlands in reducing storm damage—and the unfortunate inevitable demise of much of these important wetlands. I anticipate making one or two posts per week there, and more frequent posts when there is a tropical cyclone worthy of attention. At present, there is no comments section, but the excellent staff of Yale Climate Connections has made it high priority to get a comments section up for my “Eye on the Storm” blog in the next few weeks.

The Yale site has a long history of excellent reporting on climate change—check out their 2010 interview with me, Wunderground.com’s Jeff Masters: From ‘Mad Scientist Club’ to Leading Internet Site. I look forward to being your calm at the eye of the storm for what promises to be an unforgettable 2020 hurricane season!

Jeff Masters

For more on the upcoming closure of Category 6, see our post from Wednesday, June 10.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

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Dr. Jeff Masters

Dr. Jeff Masters co-founded Weather Underground in 1995 while working on his Ph.D. in air pollution meteorology at the University of Michigan. He worked for the NOAA Hurricane Hunters from 1986-1990 as a flight meteorologist.

emailweatherman.masters@gmail.com

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