June 2023 was Earth’s warmest June in global temperature analyses that extend back to 1850. It was 1.05 degree Celsius (1.89°F) above the 20th-century average, NOAA’s National Centers for Environmental Information reported July 13. NASA, the European Copernicus Climate Change Service, and Berkeley Earth also rated it the warmest June. According to NASA, June 2023 was 1.36 degree Celsius (2.45°F) above the 1880-1920 period, which is its best estimate for when preindustrial temperatures occurred. NASA rates the margin of error of its annual temperature measurement at 0.05 degree Celsius (.09°F).
The extreme planetary warmth continued into the first week of July, with the World Meteorological Organization rating the first week of July as the planet’s warmest week on record, surpassing a week in mid-August of 2016 when global warmth was boosted by a strong El Niño event.
Land areas had their warmest June on record in 2023, with global ocean temperatures also the warmest, according to NOAA. This marked the third consecutive month with record-high ocean temperatures. Temperatures in the North Atlantic and Gulf of Mexico during June were particularly extreme (see Tweets below).
Africa had its third-warmest June on record (tied with 2017), while South America, Europe, and Asia (tied with 2010) each had their fourth-warmest June. Oceana had its sixth-warmest June and North America had its seventh-warmest.
The year-to-date period of January-June is the third-warmest on record. And according to NOAA’s latest Global Annual Temperature Rankings Outlook and the statistical model it uses, there’s a 20% chance of 2023 being the warmest year on record; this is a boost from the odds given last month, which were put at 13%. Berkeley Earth gives an 81% chance that 2023 will be the warmest year on record, and NASA climate scientist Gavin Schmidt puts these odds at 50%. If El Niño continues to strengthen as predicted (see below), it’s very possible that 2024 will be even warmer than 2023.
NOAA said that the contiguous U.S. experienced a near-average June for temperature and precipitation. Three states – Minnesota, North Dakota, and Louisiana – had a top-10 warmest June; West Virginia and North Carolina had a top-10 coldest June.
After experiencing its warmest May on record, Canada also had its warmest June, helping cause a record wildfire season. On June 28 – with fire season less than half over – Canada’s wildfire season surpassed the record for the largest area burnt for any full year since at least 1963.
Part of the reason for the unusually hot and dry May and June in Canada and the resulting record levels of wildfire smoke transported into portions of the U.S. was a “stuck” jet stream pattern that brought persistent high pressure over Greenland. This kind of pressure pattern has been made more likely because of lower spring snow cover as a result of global warming, according to a June paper by Preece et al., Summer atmospheric circulation over Greenland in response to Arctic amplification and diminished spring snow cover. The authors argued that low spring North American snow cover enforces a wavier atmospheric jet stream that tends to support an unusually strong ridge of high pressure over Greenland – exactly the pattern observed in 2023.
El Niño intensifies
El Niño conditions strengthened over the past month in the eastern tropical Pacific and were hovering near the threshold between weak and moderate strength based on sea surface temperatures in the Niño-3.4 region. NOAA declared the start of the El Niño event on May 8, and in their July 13 discussion, they gave an 81% chance of at least a moderate El Niño developing by the November-January period. An event that becomes “historically strong” (seasonally averaged Niño-3.4 ≥ 2.0°C), rivaling the winters of 1997-98 or 2015-16, was given an approximately 20% chance.
NOAA’s and Columbia University’s International Research Institute for Climate and Society ENSO forecast for the peak portion of the Atlantic hurricane season (August-September-October) is a 0% chance of La Niña, a 5% chance of neutral conditions, and a 95% chance of El Niño. El Niño events tend to suppress Atlantic hurricane formation because of an increase in wind shear over the Main Development Region for hurricanes, particularly over the Caribbean. However, with record-warm waters in place over much of the North Atlantic, the season may be more active than usual for an El Niño year.
Arctic sea ice: 13th-lowest June extent on record
Arctic sea ice extent during June 2023 was the 13th-lowest in the 45-year satellite record, according to the National Snow and Ice Data Center. Climate scientist Judah Cohan had this to say in late May about how the rapid loss of snow cover over Canada this spring contributed to the relatively slow melt of the arctic sea ice so far in 2023: “The argument could be made that spring snow cover fell on its sword to preserve summer arctic sea ice. Snow cover has retreated rapidly across the continental high latitudes. Rapid snow melt is favorable for the northward shift of heat domes, creating a ‘ring of fire’ pattern that helps to preserve sea ice.” May was dominated by a low pressure centered near the North Pole, which insulated the central Arctic from the continental heat. However, by the end of June, this pattern had weakened, allowing more rapid melting of arctic sea ice.
Antarctic sea ice: lowest on record
Antarctic sea ice extent in June was by far the lowest on record, more than four standard deviations below the long-term average (see Tweet below).
Notable global heat and cold marks for June 202
The information below is courtesy of Maximiliano Herrera. Follow him on Twitter: @extremetemps
- Hottest temperature in the Northern Hemisphere: 51.8°C (125.2°F) at Shahdad, Iran, June 23;
- Coldest temperature in the Northern Hemisphere: -31.2°C (-24.2°F) at Summit, Greenland, June 3;
- Hottest temperature in the Southern Hemisphere: 37.2°C (99.0°F) at Pedro Afonso, Brazil, June 2, and Porto Nacional, Brazil, June 17; and
- Coldest temperature in the Southern Hemisphere: -79.2°C (-110.6°F) at Concordia, Antarctica, June 5.
Major weather stations in June: 82 all-time heat records, no all-time cold records
Among global stations with a record of at least 40 years, 82 set, not just tied, an all-time heat record in June, and no stations set an all-time cold record:
Dongchuan (China) max. 42.2°C, June 1;
Jingdong (China) max. 39.1°C, June 1;
Yimen (China) max. 36.1°C, June 1;
Huaning (China) max. 36.0°C, June 1;
Fumin (China) max. 35.9°C, June 1;
Muoding (China) max. 35.7°C, June 1;
Wuding (China) max. 35.6°C, June 1;
Jiang Chuan (China) max. 35.3°C, June 1;
Shilin Yi (China) max. 35.2°C, June 1;
Da Yao (China) max. 35.2°C, June 1;
Chuxiong (China) max. 35.1°C, June 1;
Chengjiang (China) max. 34.7°C, June 1;
Anning (China) max. 34.6°C, June 1;
Nanhua (China) max. 34.5°C, June 1;
Luxi (China) max. 34.5°C, June 1;
Qujing (China) max. 34.3°C, June 1;
Songming (China) max. 34.1°C, June 1;
Zhanyi (China) max. 33.9°C, June 1;
Jinning (China) max. 33.7°C, June 1;
Tonghai (China) max. 33.3°C, June 1;
Eryuan (China) max. 33.1°C, June 1;
Shizong (China) max. 33.1°C, June 1;
Chenggong (China) max. 32.9°C, June 1;
Malong (China) max. 32.5°C, June 1;
Jalturovsk (Russia) max. 37.9°C, June 3;
Alexandrovskoe (Russia) max. 36.1°C, June 4;
Laryak (Russia) max. 34.9°C, June 4;
Ciudad Guzman (Mexico) max. 41.0°C, June 4;
Majsk (Russia) max. 37.1°C, June 5;
Severnoe (Russia) max. 35.7°C, June 5;
Pervomajskoe (Russia) max. 35.8°C, June 6;
Baevo (Russia) max. 39.6°C, June 7;
Barnaul (Russia) max. 38.5°C, June 7;
Novosibirsk (Russia) max. 37.3°C, June 7;
Toguchin (Russia) max. 37.2°C, June 7;
Mariinsk (Russia) max. 36.4°C, June 7;
Tjuhtet (Russia) max. 35.4°C, June 7;
Bogotol (Russia) max. 35.1°C, June 7;
Zdvinsk (Russia) max. 38.0°C, June 8;
Janakpur (Nepal) max. 42.5°C, June 9;
Okhaldhunga (Nepal) max. 32.5°C, June 9;
Vishakhapatnam Waltair (India) max. 43.4°C, June 10;
Guadalajara (Mexico) max. 40.5°C, June 13;
Lagos de Moreno (Mexico) max. 38.5°C, June 13;
Guanajuato (Mexico) max. 39.2°C, June 15;
Zacatecas La Bufa (Mexico) max. 35.0°C, June 15;
Ciudad Victoria (Mexico) max. 47.4°C, June 18;
Zabol (Iran) max. 49.8°C, June 18;
Torreon (Mexico) max. 45.7°C, June 19;
Monclova (Mexico) max. 46.3°C, June 20;
San Angelo (Texas, USA) max. 45.6°C, June 20;
Ozona (Texas, USA) max. 45.0°C, June 20;
Kingsville (Texas, USA) max. 44.4°C, June 20;
Del Rio (Texas, USA) max. 46.1°C, June 21;
Rocksprings (Texas, USA) max. 42.8°C, June 21;
Sonora (Texas, USA) max. 43.9°C, June 21;
Chihuahua (Mexico) max. 42.0°C, June 21;
Tanghekouzhen (China) max. 41.8°C, June 22;
Huairou (China) max. 41.2°C, June 22;
Zhaitang (China) max. 41.1°C, June 22;
Miyun (China) max. 40.6°C, June 22;
Foye Peak (China) max. 34.4°C, June 22;
Dagang (China) max. 41.8°C, June 22;
Tianjin (China) max. 41.5°C, June 22;
Sigi (China) max. 41.1°C, June 22;
Wu Qing (China) max. 40.9°C, June 22;
Beichen (China) max. 41.6°C, June 22;
Langfang (China) max. 41.4°C, June 22;
Gu’an (China) max. 40.8°C, June 22;
Zunhua (China) max. 40.2°C, June 22;
Wudi (China) max. 41.3°C, June 22;
Yang Xin (China) max. 40.8°C, June 22;
Jimo (China) max. 39.9°C, June 23;
Anqiu (China) max. 40.4°C, June 23;
Qixia (China) max. 40.2°C, June 23;
Pingduc (China) max. 40.2°C, June 23;
Laixi (China) max. 39.9°C, June 23;
Cuona (China) max. 18.5°C, June 23;
Pinar del Rio (Cuba) max. 37.0°C, June 24;
Funchal (Portugal) max. 38.7°C, June 27;
Quinta Grande (Portugal) max. 39.1°C, June 27; and
Ennadai Lake (Canada) max. 32.3°C, June 29.
Five all-time national/territorial heat records set or tied in 2023
As of the end of June, five nations or territories had set or tied an all-time national heat record in 2023:
Thailand: 45.4°C (113.7°F) at Tak Agromet, April 15;
Laos: 42.7°C (108.9°F) at Luang Prabang, April 18; beaten one day later with 42.9°C (109.2°F) at Sayaburi, April 19; beaten again on May 6 and May 7 with 43.5°C (110.3°F) at Luang Prabang;
Vietnam: 44.1°C (111.4°F) at Hoi Xuan, May 6; beaten again with 44.1°C (111.4°F) at Tuong Duong, May 7;
Singapore: 37.0°C (98.6°F) at Ang Mo Kio, May 13 (tie); and
Chad: 48.0°C (118.4°F) at Faya, May 25.
Three all-time national/territorial cold records set or tied in 2023
As of the end of June 2023, three nations or territories had set or tied an all-time national cold record:
Myanmar: -6.0°C (21.2°F) at Hakha, Jan. 17 (tied);
China: -53.0°C (-63.4°F) at Jintao, Jan. 22; and
Cyprus: -12.8°C (8°F) at Trodos Mt. Station, Feb. 8 (tied).
Fifty-five additional monthly national/territorial heat records and four additional monthly cold records beaten or tied
In addition to the five all-time heat records listed above (plus one, for the records set in two different months in Laos), 55 additional monthly all-time heat records have been set in 2023, for a total of 61 all-time monthly heat records:
- Jan. (13): Czech Republic, Liechtenstein, Netherlands, Denmark, Poland, Belarus, Lithuania, Latvia, Romania, Moldova, Ukraine, Cyprus, Nigeria
- Feb. (4): Chile, Taiwan, Pakistan, Cyprus
- March (3): Botswana, Vietnam, Taiwan
- April (12): Cabo Verde, Botswana, Turkmenistan, Mauritius, Antigua and Barbuda, Spain, Morocco, Portugal, Andorra, Saba, St. Barthelemy, Laos
- May (9): Mauritius, Solomon Islands, Botswana, Cambodia, Cocos Islands, Panama, Saba, Maldives, French Guiana
- June (14): Botswana, Vietnam, Tuvalu, Hong Kong, Mauritius, Aruba, Saba, Senegal, Costa Rica, China, Chad, Solomon Islands, Morocco, French Guiana
In addition to the three all-time cold records listed above, four nations or territories have set a monthly all-time cold record in 2023, for a total of seven monthly cold records:
- Feb. (1): Montenegro
- March (2): St. Eustatius, Martinique
- June (1): Finland
Hemispherical and continental temperature records through June 2023
- Lowest temperature reliably recorded in January in the Southern Hemisphere: -51.2°C (-60.2°F) at Concordia, Antarctica, Jan. 31; and
- Highest temperature ever recorded in April in Europe: 38.8°C (101.8°F) at Cordoba, Spain, April 27.
Bob Henson contributed to this post.
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