October 2019: Earth’s Second Warmest October on Record

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American

October 2019 was the planet's second warmest October since record keeping began in 1880, said NOAA's National Centers for Environmental Information (NCEI) on November 18. NASA also rated October 2019 as the second warmest October on record, a scant 0.05°C behind the record-setting October of 2015.

Global ocean temperatures during October 2019 were the second warmest on record, according to NOAA, and global land temperatures were also the second warmest on record. Global satellite-measured temperatures in October 2019 for the lowest 8 km of the atmosphere were the second or third warmest in the 42-year record, according to the University of Alabama Huntsville (UAH) and RSS, respectively.

2019 almost certain to be among the 5 warmest years in Earth’s recorded history

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The January through October year-to-date period was the second warmest on record globally, just 0.09°C behind 2016, according to NOAA. Their global annual temperature ranking outlook indicated that it is virtually certain that 2019 will end among the top five warmest years in Earth’s history (and virtually certain that it will not be the warmest year on record).

This means that the six warmest years on record globally since 1880 will end up being the last six years—2014 through 2019—with the peak occurring during the strong El Niño year of 2016. NOAA gave an 86% chance that 2019 would be the second warmest year on record, behind 2016. Many regions of the globe are on pace to have their warmest year on record, including Southeast Asia, southern Africa, and portions of Mexico, Alaska, Europe, and Australia.

This near-record global warmth in 2019 is all the more remarkable since it is occurring during the minimum of the weakest solar cycle in 100+ years, and during a year when a strong El Niño has not been present (though a weak El Niño was present in the first half of 2019, ending in July). Record-warm global temperatures typically occur during strong El Niño events, and when the solar cycle is near its maximum. The near-record warmth of 2019 is thus a testament to how greatly human-caused global warming is impacting the planet.

Two billion-dollar weather disasters in October 2019

Two billion-dollar weather-related disasters hit the Earth last month, according to the October 2019 Catastrophe Report from insurance broker Aon: Typhoon Hagibis (Japan, $10+ billion), and drought in China ($2.2 billion). The 2019 tally of billion-dollar weather disasters was 25 as of the end of October. Ten of these disasters were in the U.S., making it the fifth year in a row for ten or more billion-dollar weather disasters—an unprecedented occurrence. Fifteen of the 30 years since 1990 have seen 25 or more billion-dollar weather disasters globally. The record is 44, set in 2011. Here are this year’s billion-dollar weather disasters, as tabulated by Aon:

Typhoon Hagibis, 10/1 – 10/2, $10+ billion, 95 killed
Flooding, India, 6/1 – 10/5, $10+ billion, 1850 killed
Flooding, Central U.S., 5/1 – 7/31, $10+ billion, 0 killed
Typhoon Lekima, China, 6/1 – 7/1, $10+ billion, 73 killed
Flooding, China, 6/1 – 7/1, $8.5+ billion, 225 killed
Flooding, Iran, 3/17 - 4/9, $8.3 billion, 77 killed
Hurricane Dorian, 8/31 – 9/7, Bahamas, U.S., and Canada, $7+ billion, 664 dead or missing
Typhoon Faxai, Japan, 9/8 – 9/9, $7 billion, 3 killed
Flooding, Central U.S., 3/12 – 4/30, $5 billion, 3 killed
Severe Weather, Rockies, Plains, Midwest, Southeast U.S., 5/26 – 5/31, $4 billion, 3 killed
Flooding, Spain, 9/11 – 9/15, $2.4 billion, 7 killed
Flooding, Argentina, Uruguay, 1/1 - 1/20, $2.3 billion, 5 killed
Drought, China, 10/1 – now, $2.2 billion, 0 killed
Cyclone Fani, India, Bangladesh, 5/3 – 5/5, $2+ billion, 89 killed
Tropical Storm Imelda, Texas/Louisiana (U.S.), 9/17 – 9/20, $2+ billion, 1 killed
Cyclone Idai, Mozambiqe, Zimbabwe, Malawi, 3/3 - 3/18, $2 billion, 1007+ killed
Flooding, Australia, 1/28 - 2/7, $1.9 billion, 3 killed
Drought, India, 1/1 – now, $1.75 billion, 0 killed
Severe Weather, Plains, Midwest U.S., 3/23 – 3/25, $1.5 billion, 0 killed
Windstorm Eberhard, Central & Western Europe, 3/10, $1.5 billion, 2 killed
Severe Weather, Central/Eastern U.S., 2/22 - 2/26, $1.4 billion, 4 killed
Severe Weather, Plains, Midwest, Southeast U.S., 5/4 – 5/10, $1.2 billion, 1 killed
Severe Weather, Plains, Midwest, Southeast, Northeast U.S., 4/12 – 4/15, $1.1 billion, 9 killed
Severe Weather, Central Europe, 6/10 – 6/12, $1.1 billion, 0 killed
Severe Weather, Plains, Midwest, Southeast U.S., 3/12 – 3/17, $1 billion, 5 killed

Neutral El Niño conditions reign

NOAA’s November 14 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, though warmer than average, have been below the 0.5°C above-average threshold need to be considered El Niño conditions.

Forecasters at NOAA and the International Research Institute for Climate and Society (IRI) are calling for a roughly 70% chance of neutral conditions continuing through winter, and a 60 – 65% chance of neutral conditions continuing into the spring of 2020. They put the odds of an El Niño forming by spring at about 20 - 25%, and the odds of a La Niña event at 10 - 15%.

October 2019 Arctic sea ice extent: lowest October extent on record

Arctic sea ice extent began at the third lowest in the 41-year satellite record on October 1, but dropped to the lowest on record during the period October 13 – 30. The month finished with the lowest October ice extent on record, surpassing the previous record set in 2012, according to the National Snow and Ice Data Center (NSIDC). From the period October 31 – November 17, though, sea ice extent was the 2^nd or 3^rd lowest on record, behind the record-setting years of 2016 and 2012.

In Antarctica, sea ice extent in October 2019 was the tenth-lowest for October since satellite records began in 1979.

Notable heat and cold marks for October 2019

Hottest temperature in the Northern Hemisphere: 47.6°C (117.7°F) at Al Wafra, Kuwait, 3 October
Coldest temperature in the Northern Hemisphere: -50.3°C (-58.5°F) at Geo Summit, Greenland, 22 and 23 October
Hottest temperature in the Southern Hemisphere: 46.7°C (116.1°F) at Massangena, Mozambique, 8 October
Coldest temperature in the Southern Hemisphere: -73.3°C (-99.9°F) at Concordia, Antarctica, 8 October

(Courtesy of Maximiliano Herrera)

Major weather stations that set (not tied) all-time heat or cold records in October 2019

Among global stations with a period of record of at least 40 years tracked by Maximiliano Herrera, 12 set new all-time heat records in October. There were no stations that set all-time cold records.

Tobago Airport (Trinidad and Tobago) max. 34.8°C, 16 October
Middle Point (Australia) max. 42.5°C, 20 October
Serang (Indonesia) max. 37.4°C, 22 October
Makassar (Indonesia) max. 39.0°C, 2 October
Buffalo Range (Zimbabwe) max. 45.9°C, 28 October: New national record high for Zimbabwe
Matopos (Zimbabwe) max. 38.7°C, 28 October
Gweru (Zimbabwe) max. 37.4°C, 28 October
Chimoio (Mozambique) max. 40.9°C, 28 OctoberPunda Maria (South Africa) max. 45.6°C, 28 October
Levubu (South Africa) max. 43.4°C, 28 October
Mara (South Africa) max. 42.8°C, 28 October
Oran Airport (Argentina) max. 44.5°C, 28 October

Twenty all-time national/territorial heat records set or tied in 2019

As of November 15, all-time high temperature records have been tied or broken in twenty of the world’s nations and territories, making 2019 the second most prolific year on record for all-time national heat records. The largest number of all-time national/territorial heat records set or tied in a single year was the 22 heat records that occurred in 2016, according to international records researcher Maximiliano Herrera; 2017 holds third place with 14 heat records. Here are 2019’s national heat records, as of November 15, with notations by Herrera at the end:

Christmas Island (Australia): 31.6°C (88.9°F), 19 January
Reunion Islands (France): 37.0°C (98.6°F), 25 January
Angola: 41.6°C (106.9°F), 22 March
Togo: 43.5°C (110.3°F), 28 March (later tied on 4 April)
Vietnam: 43.4°C, (110.1°F), 20 April
Jamaica: 39.1°C (102.4°F) at Shortwood Teacher’s College, 22 June
France: 46.0°C (114.8°F) at Verargues, 28 June
Andorra: 39.4°C (102.9°F) at Borda Vidal, 28 June
Cuba: 39.1°C (102.4°F) at Veguitas (Cuba), 30 June
Jersey (crown dependency of Britain): 36.0°C (96.8°F) at Jersey Airport, 23 July (record tied)
Belgium: 41.8°C (107.2°F) at Begijnendijk, 25 July
Germany: 41.2°C (108.7°F) at Tonisvorst and Duisburg, 25 July*
Luxembourg: 40.8°C (105.4°F) at Steinsel, 25 July
Netherlands: 40.7°C (105.3°F) at Gilze Rijen, 25 July
United Kingdom: 38.7°C (101.7°F) at Cambridge, 25 July
Norway: 35.6°C (96.1°F) at Laksfors, 27 July (record tied)**
Syria: 50.0°C (122.0°F) at Hasakah, 13 August***
Wake Island (United States Minor Outlying Islands): 36.6°C (97.9°F) at Wake Airfield, 15 August
Guadeloupe (French territory): 36.6°C (97.9°F) at Vieux Habitants, 9 September
Zimbabwe: 45.9°C (114.6°F) at Buffalo Range, 28 October

* The official national record of 42.6°C measured the same day at Lingen is irregular and totally incompatible with nearby stations data and with the atmospheric conditions. The station has a history of overexposure and of being unreliable and is set to be moved. Despite this, the record was made official by the German DWD. Estimated overexposure is estimated to be about 2°C.

** This tied record was dismissed by the Norwegian Met. Service on weak grounds despite being reliable and compatible with nearby stations data and the atmospheric conditions. Confoundingly, the totally unreliable and irregular records set in August 1901—30 years before the installment of the first reliable temperature shelter with a Stevenson Screen in Oslo—have not been dismissed.

*** The Hasakah, Syria station has 1°C precision. The max temperature of 50.0°C is supported by nearby stations, so the record can be accepted.

No all-time national cold records have been set thus far in 2019. Most nations do not maintain official databases of extreme temperature records, so the national temperature records reported here are in many cases not official. If you reproduce this list of extremes, please cite Maximiliano Herrera as the primary source of the weather records. Jérôme Reynaud also tracks all-time and monthly national extreme temperature records at geoclimat.org (in French language).

One hundred eleven additional monthly national/territorial heat records beaten or tied in 2019 as of November 15

In addition to the 20 all-time any-month heat records listed above, 111 national monthly records have also been beaten or tied in 2019. If we add together these totals, there have been 131 monthly national/territorial heat records beaten or tied in 2019; zero monthly cold records have been set:

January (5): Micronesia, Paraguay, Angola, Equatorial Guinea, Palau
February (19): Chile, Marshall Islands, Guyana, United Kingdom, Denmark, Sweden, Netherlands, Belgium, Luxembourg, Andorra, Austria, Hungary, Jersey, Guernsey, Slovakia, San Marino, Slovenia, Angola, Papua New Guinea
March (5): Australia, Marshall Islands, India, Kenya, Northern Marianas
April (7): Angola, Togo, French Southern Territories, Mayotte, Taiwan, Kenya, Mauritius
May (12): Kenya, Indonesia, Niger, French Southern Territories, Syria, Tonga, Laos, Vietnam, Japan, Israel, Cyprus, Turkey
June (16): India, Tonga, Namibia, Lithuania, Senegal, Qatar, Chile, Laos, Vietnam, Germany, Czech Republic, Poland, Switzerland, Luxembourg, Liechtenstein, St. Barthelemy
July (9): Iran, Wallis and Futuna, Namibia, Jordan, Israel, Hong Kong, Chile, Bonaire, Mauritius
August (5): Taiwan, Cape Verde, Namibia, Wallis and Futuna, Kenya
September (13): Oman, Brunei, Niger, Saba, Nicaragua, Paraguay, Brazil, Solomon Islands, Morocco, Comoros, Laos, Jamaica, Kenya
October (16): Hong Kong, Mongolia, Morocco, Micronesia, Qatar, Kuwait, North Korea, China, Saba, Thailand, Mozambique, Botswana, Malawi, Falkland Islands, South Georgia and Sandwich Islands, French Southern Territories
November (3):St Pierre et Miquelon, Haiti, Syria, Tuvalu

(Courtesy of Maximiliano Herrera)

Hemispheric and continental temperature records in 2019

- Highest minimum temperature ever recorded in the Southern Hemisphere: 35.9°C (96.6°F) at Noona, Australia, 18 January. The record was beaten again on 26 January, with a minimum temperature of 36.6°C (97.9°F) recorded at Borrona Downs, Australia. This is also the highest minimum temperature on record for the globe for the month of January.

-Highest temperature ever recorded in March globally: 48.5°C (91.4°F) at Emu Creek, Australia, on 11 March.

- Highest temperature ever recorded in Asia in March: 46.9°C (116.4°F) at Kapde, India, 25 March. The data comes from a state (not central government) station, and may not be officially recognized, but is supported by data from several nearby stations.

- Highest minimum temperature ever recorded in June in the Southern Hemisphere: 28.9°C (84.0°F) at Funafuti, Tuvalu on 15 June.

- Highest minimum temperature ever recorded in August in the Southern Hemisphere (tie): 28.2°C (82.8°F) at Funafuti, Tuvalu on 15 August.

- Highest temperature ever recorded in October in the Northern Hemisphere: 47.6°C (117.7°F) at Al Wafra, Kuwait on 3 October.

- Highest minimum temperature ever recorded in October: 33.0°C (91.4°F) at Sedom, Israel on 15 October.