August 2024 was Earth’s warmest August in analysis of global data going back to 1850, and the past three months (summer in the Northern Hemisphere and winter in the Southern Hemisphere) were the warmest June-to-August period on record, NOAA’s National Centers for Environmental Information, or NCEI, reported September 12. August 2024 was 0.01 degrees Celsius (0.02°F) warmer than August 2023. Both came in well above all preceding Augusts, and the past 11 Augusts have all been warmer than any others on record.
As opposed to being focused in one region or another, the record heat was unusually widespread. Around 10.3% of the world’s surface experienced record heat, beating the previous August record extent set in 2023 of 9.5%. August also was the 15th consecutive month of record-high global temperatures, itself an unprecedented streak in analysis dating back to 1980.
NASA placed August at 1.53 degrees Celsius (2.76°F) above the 1880-1899 period, its best estimate for when preindustrial temperatures last occurred. This beat the previous August record (from 2023) by 0.11 degrees Celsius (0.20°F).
The European Copernicus Climate Change Service rated August 2024 as tied with August 2023 as the warmest August on record. Minor differences in rankings often occur among various research groups, the result of different ways they handle data-sparse regions such as the Arctic.
Land areas had their warmest August on record in 2024, according to NOAA, and global ocean temperatures were the second warmest on record. The recent record heat in the oceans has brought on a global coral bleaching event, the fourth one in recorded history (1998, 2010, 2014-17, and now 2024). For the period June-August, a record 5% of the global oceans had an average sea surface temperature of at least 30 degrees Celsius (86°F)(see Tweet below).
A record 5% of the global ocean had an average sea surface temperature of 30C or warmer during Jun-Aug 2024. Historically, less than 1% was this warm. pic.twitter.com/xUOU5RCuWv
— Brian Brettschneider (@Climatologist49) September 6, 2024
It was the warmest August on record for Europe and Oceania, second warmest for Asia, third warmest for Africa and North America, and sixth warmest for South America. The Caribbean had its warmest August on record, and the Main Development Region for hurricanes in the Atlantic had its second warmest August.
Despite this intense near-surface warmth, hurricane formation was largely quashed in August by extremely warm air a few miles above sea level, which reduced the necessary instability. Satellite-measured temperatures of the planet’s lower atmosphere (the lowest few miles) in August were the warmest on record for the month globally.
For the year to date, the January-to-August global surface temperature ranked warmest in NOAA’s 175-year record, running a full 0.19°C (0.34°F) above the previous record from Jan-Aug 2016. As Earth’s atmosphere continues to warm, the sharpest annual peaks typically occur in the second year of a strong El Niño event, such as the events in 2015-16 and 2023-24. According to NOAA/NCEI’s statistical analysis, there is now a 97.2% chance that 2024 will rank as the warmest year on record and a 100% chance that it will rank in the top five. Climate scientist Zeke Hausfather says 2024 is virtually certain to be the warmest year on record, while climate scientist Gavin Schmidt says a record outcome is “almost guaranteed…and not by a little.”
August 2024 was the wettest August on record globally for atmospheric moisture and 14th-consecutive wettest month on record, as measured via precipitable water in analysis dating back to 1940 (see Tweet below). A warmer atmosphere and ocean allows more moisture to evaporate into the air.
❗️ With data in through August 2024, the globe has now set atmospheric moisture records for 14 consecutive months, with the streak starting in July 2023…
This has influenced an increase in the coverage of upper decile (top 10%) rainfall events.
The increase in water vapor, a… pic.twitter.com/qt7I0mZzLB
— Ben Noll (@BenNollWeather) September 6, 2024
Hottest summer on record for five U.S. states and dozens of cities
According to NOAA, the contiguous U.S. had its 15th-warmest August and fourth-warmest summer. However, there was stark regional disparity in this summer’s temperatures. Nine states centered on the Midwestern Corn Belt had summer temps averaging near the midpoint of the last 130 years, whereas the West and Northeast were scorching. Five states – California, Arizona, Maine, Florida, and New Hampshire – had their hottest summer on record, and 20 other states had a top-10 hottest summer.
Summers have gotten over 4.5 degrees Fahrenheit hotter over much of the Western U.S. in recent decades, and 1-3 °F hotter over most of the rest of the country (see Tweet below).
Let’s check in and see how summer (Jun-Aug) temperatures are trending over the last 85 years. [Note: Great Lakes temperatures have an assimilation problem before 2014.] pic.twitter.com/faDVDNbQ90
— Brian Brettschneider (@Climatologist49) September 5, 2024
Weather historian Chris Burt tracks the weather statistics for 304 major U.S. weather stations with a long-term period of record, and these are the places in his database that set an all-time record for hottest summer in 2024 (temperatures given in degrees Fahrenheit; POR refers to period of record):
HOTTEST CLIMATOLOGICAL SUMMER ON RECORD 2024
SITE/POR NEW RECORD OLD RECORD (YEAR)
Las Vegas, NV (1937-) 96.2 93.7 (2018)
Needles, CA (1893-) 99.4 98.7 (2018)
Death Valley, CA (1911-) 104.5 104.2 (2018)
Yuma , AZ (1895-) 95.7 95.3 (1994)
Blythe, CA (1948-) 97.4 96.3 (1961)
Barstow, CA (1948-) 91.1 91.0 (2021)
Phoenix, AZ (1895-) 98.9 97.0 (2023)
Flagstaff, AZ (1898-) 68.4 66.6 (1981)
Winslow, AZ (1898-) 80.7 79.4 (2021)
Tucson, AZ (1894-) 90.0 tie 90.0 (2020)
Palm Springs, CA (1922-) 96.2 95.3 (2021)
Sacramento, CA (1877-) 80.3 79.3 (2020)
Napa, CA (1893-) 71.1 70.9 (2017)
Stockton, CA (1893-) 79.5 79.1 (1961)
Redding, CA (1893-) 84.4 84.1 (2017)
Ukiah, CA (1893-) 76.9 76.7 (2021)
San Jose, CA (1893-) 72.8 72.1 (1996)
Reno NV (1893-) 77.5 77.4 (2021)
Caribou, ME (1939-) 67.3 66.3 (2018)
St. Johnsbury, VT (1894-) 70.3 70.0 (1949)
Hartford, CT (1905-) 75.4 74.4 (1973)
Ft. Lauderdale, FL (1913-) 84.6 tie 84.6 (2010)
Tallahassee, FL (1892-) 84.9 84.4 (2011)
Lakeland, FL (1949-) 84.8 84.6 (2023)
Punta Gorda, FL (1914-) 85.7 84.7 (2023)
Grand Junction, CO (1892-) 80.1 79.5° (1984)
Wash DC-Dulles (1962-) 78.1 77.8° (2010)
Several stations in Florida that Mr. Burt does not track also had a record-hot summer in 2024 (POR refers to the length of the station’s period of record):
Plant City, FL: 86.5, tied with 2023, POR 1893-
Winter Haven, FL: 85.1, old record 84.8 in 1989 and 1998, POR 1941-
Ruskin/Tampa Bay, FL WFO: 85.1, old record 83.8 in 2023, POR 1976-
Wow by 2 F! https://t.co/0YUNyhCK00
— Jeff Berardelli (@WeatherProf) September 3, 2024
The tally of U.S. billion-dollar weather disasters so far in 2024 has been 20, and this does not include Hurricanes Debby and Francine, which are both expected to be billion-dollar disasters. The average number of billion-dollare disasters for a full year for the most recent five years (2019–2023) is 20.4; the record was 28, set in 2023.
Neutral ENSO conditions still expected to transition to La Niña this fall
The 2023-24 El Niño event in the Eastern Pacific ended during May, and neutral conditions remain in place, NOAA reported in its latest monthly discussion of the state of the El Niño/Southern Oscillation, or ENSO. La Niña is still projected to prevail during 2024-25, but the slower-than-expected pace of development thus far has chipped away slightly at the probabilities in recent months.
According to the official NOAA probabilistic forecast issued September 12, which is based on expert judgment drawing from observations and model data, there is now a 71% chance of La Niña conditions developing by September-October-November. La Niña conditions are expected to persist into the Northern Hemisphere winter of 2024-2025, with a 74% chance during November-January. The most likely outcome is a weak La Niña event rather than a moderate or strong one, according to NOAA
A separate joint outlook from NOAA and Columbia University’s International Research Institute for Climate and Society, which is issued in the later part of each month and based purely on model simulations, has been somewhat less bullish on La Niña for some time. For the remainder of the Atlantic hurricane season (September-November), the mid-August NOAA/IRI forecast called for a 41% chance of La Niña, a 55% chance of ENSO-neutral, and a mere xx% chance of El Niño.
El Niño conditions tend to suppress Atlantic hurricane activity through an increase in wind shear, but La Niña conditions tend to have the opposite effect. There’s not a lot of difference in Atlantic hurricane activity between La Niña and neutral conditions.
Arctic sea ice: 4th-lowest August extent on record
Arctic sea ice extent during August 2024 was the fourth-lowest in the 46-year satellite record, according to the National Snow and Ice Data Center, or NSIDC. The Arctic had its xxx-warmest August on record. Both the northern and southern Northwest Passage routes through Canadian waters have largely cleared of ice, as has the Northern Sea Route along the northern coast of Russia. Satellite imagery showed that open water appeared at the North Pole on August 25.
As of August 14, the 2024 melt season for the Greenland Ice Sheet was above the 1991 to 2020 average, but the total number of melt days and peak melt area for Greenland were within the mid-range of the last 24 years. Temperatures were near the 1991 to 2021 average.
Antarctic sea ice extent in August was the second-lowest on record, well below all other years except for 2023. The Antarctic region had its xxx-warmest August on record.
Notable global heat and cold marks for August 2024
The information below is courtesy of Maximiliano Herrera. Follow him on Twitter @extremetemps:
- Hottest temperature in the Northern Hemisphere: 52.0°C (125.6°F) at Jahra, Kuwait (August 18) and Shush, Iran (Aug. 27);
- Coldest temperature in the Northern Hemisphere: -29.2°C (-20.6°F) at Summit, Greenland, August 21;
- Hottest temperature in the Southern Hemisphere: 42.2°C (108.0°F) at Culaba, Brazil, August 18; and
- Coldest temperature in the Southern Hemisphere: -75.5°C (-103.9°F) at Vostok, Antarctica, August 14.
Major weather stations in August: 100 all-time heat records, 0 all-time cold records
Among global stations with a record of at least 40 years, 100 set, not just tied, an all-time heat record in August; no stations set an all-time cold record:
Nimi (Japan) max. 36.9°C, August 1;
Kake (Japan) max. 39.1°C, August 1;
Taketa (Japan) max. 38.1°C, August 1;
Gunge (Japan) max. 38.1°C, August 2;
Kazeya (Japan) max. 39.9°C, August 2;
Kyojo (Japan) max. 35.8°C, August 2;
Yanai (Japan) max. 36.7°C, August 2;
Dezaifu (Japan) max. 39.3°C, August 2;
Minhang (China) max. 40.9°C, August 2;
Zhuji (China) max. 41.5°C, August 2;
Wando (South Korea) max. 37.0°C, August 3;
Hangzhou (China) max. 41.9°C, August 3;
Qingpu (China) max. 40.9°C, August 3;
Tonglu (China) max. 42.4°C, August 3;
Zhuji (China) max. 42.5°C, August 3;
Yiwu (China) max. 42.8°C, August 3;
Dongyang (China) max. 42.4°C, August 3;
Yongkang (China) max. 42.3°C, August 3;
Jinyun (China) max. 41.7 3 August
Gunge (Japan) max. 38.2°C, August 3;
Chiya (Japan) max. 35.1°C, August 3;
Miyoshi (Japan) max. 38.5°C, August 3;
Mizuho (Japan) max. 36.8°C, August 3;
Kyojo (Japan) max. 36.1°C, August 3;
Takamori (Japan) max. 35.0°C, August 3;
Takachino (Japan) max. 37.4°C, August 3;
Satsuma (Japan) max. 38.1°C, August 3;
Okuchi (Japan) max. 38.0°C, August 3;
Takinomiya (Japan) max. 38.1°C, August 4;
Omuta (Japan) max. 38.1°C, August 4;
Arikawa (Japan) max. 36.8°C, August 4;
Taimei (Japan) max. 38.4°C, August 4;
Hondo (Japan) max. 38.1°C, August 4;
Hitoyoshi (Japan) max. 38.2°C, August 4;
Ue (Japan) max. 38.2°C, August 4;
Koniya (Japan) max. 35.2°C, August 4;
Longquan (China) max. 42.2°C, August 4;
Quzhou (China) max. 42.1°C, August 4;
Jiangshan (China) max. 41.1°C, August 4;
Jiangdu (China) max. 40.7°C, August 4;
Sendai (Japan) max. 37.3°C, August 5;
Zanjan (Iran) max. 40.6°C, August 6;
Deadhorse (Alaska, USA) max. 31.7°C, August 6;
Inuvilk (Canada) max. 34.8°C, August 7;
Fort McPherson (Canada) max. 35.1°C, August 8;
Paulatuk (Canada) max. 31.0°C, August 8;
Ashibe (Japan) max. 35.0°C, August 8;
Ibusuki (Japan) max. 36.9°C, August 8;
Boca de Mao (Dominica Republic) max. 41.4°C, August 8: New national record high for Dominican Republic;
Kaminaka (Japan) max. 35.7°C, August 10;
Onoida (Japan) max. 35.7°C, August 10;
Mooka (Japan) max. 38.6°C, August 11;
Choshi (Japan) max. 35.9°C, August 11;
Kamogawa (Japan) max. 37.3°C, August 11;
Deqing (China) max. 41.6°C, August 11;
Jingzhou (China) max. 39.4°C, August 11;
Ponza (Italy) max. 37.3°C, August 11;
Naganuma (Japan) max. 36.3°C, August 12;
Atsuma (Japan) max. 34.4°C, August 12;
Shizunai (Japan) max. 33.9°C, August 12;
Isen (Japan) max. 35.8°C, August 12;
Oogaki (Japan) max. 38.8°C, August 13;
Nishiwaki (Japan) max. 39.5°C, August 13;
Birjand (Iran) max. 44.1°C, August 13;
Tabas (Iran) max. 49.7°C, August 14;
Kaseda (Japan) max. 36.4°C, August 14;
Zenica (Bosnia and Herzegovina) max. 42.7°C, August 14;
Sombor (Serbia) max. 40.6°C, August 14;
Tsujido (Japan) max. 37.0°C, August 15;
Yuki (Japan) max. 34.9°C, August 15;
Kake (Japan) max. 39.5°C, August 15;
Ikuchi (Japan) max. 37.8°C, August 15;
Hiwasa (Japan) max. 38.3°C, August 15;
Hirose (Japan) max. 39.0°C, August 15;
Tashiro (Japan) max. 36.1°C, August 15;
Nehbandan (Iran) max. 45.9°C, August 15;
Kerman (Iran) max. 42.3°C, August 15;
Owase (Japan) max. 38.8°C, August 16;
Shimizu (Japan) max. 37.2°C, August 16;
Munakata (Japan) max. 38.2°C, August 20;
Yahata (Japan) max. 37.5°C, August 20;
Yatsushiro (Japan) max. 38.7°C, August 20;
Tsuwano (Japan) max. 38.9°C, August 21;
Abilene (Texas, USA) max. 45.0°C, August 21;
Tottori (Japan) max. 39.4°C, August 22;
Kamioka (Japan) max. 37.7°C, August 22;
Yasaka (Japan) max. 36.0°C, August 22;
Ikeda (Japan) max. 37.6°C, August 22;
Yuya (Japan) max. 36.8°C, August 22;
Bungotakada (Japan) max. 37.7°C, August 22;
Dongae (South Korea) max. 38.5°C, August 22;
Rokkasho (Japan) max. 34.8°C, August 23;
Hajikizaki (Japan) max. 36.2°C, August 23;
Miyazu (Japan) max. 39.0°C, August 23;
Toyooka (Japan) max. 39.7°C, August 23;
Kahoku (Japan) max. 37.3°C, August 24;
Kousa (Japan) max. 38.9°C, August 24;
Qingzhen (China) max. 34.7°C, August 28;
Rangtang (China) max. 31.6°C, August 28; and
Banma (China) max. 29.6°C, August 28.
Sixteen all-time national/territorial heat records beaten or tied as of the end of August
Cocos Islands (Australia): 32.8°C (91.0°F), Feb. 28, Feb. 29, Apr. 7 (tie);
Costa Rica: 41.0°C (105.8°F) at Cerro Huacalito, Mar. 6; broken again with 41.5°C, Mar. 23, at the same location;
Comoros: 36.2°C (97.2°F) at Hahaya Airport, Mar. 12;
Congo Brazzaville: 39.6°C (103.3°F) at Impfondo, Mar. 13;
Maldives: 35.1°C (95.2°F) at Hanimadhoo, Mar. 24; tied at the same location on Apr. 11;
Togo: 44.0°C (111.2°F) at Mango, Mar. 31;
Mali: 48.5°C (119.3°F) at Kayes, Apr. 3;
Belize: 42.3°C (108.1°F) at Barton Creek, Apr. 10; tied on May 17 at Chaa Creek;
Chad: 48.0°C (118.4°F) at Faya, Apr. 24; tied on Jun. 5 at the same location;
Cambodia: 42.8°C (109.0°F) at Preah Viehar and Svay Leu, Apr. 27;
Laos: 43.7°C (110.7°F) at Tha Ngon, May 1; (3rd time that the previous all-time record was beaten in 2024);
Ghana: 44.6°C (112.3°F) at Navrongo, May 1;
Palau: 35.0°C (95.0°F) at Babelthuap Int. Airport, May 29 (tie); beaten again with (Palau) 35.6°C at Koror on Jun. 2; and
Egypt: 50.9°C (123.6°F) at Assuan, Jun. 7;
Mexico: 52.0°C (125.6°F) at Tepache, Jun. 20 (tie); and
Dominican Republic: 41.4°C (106.5°F), at Boca de Mao, Aug. 8.
One hundred fifty-six additional monthly national/territorial heat records beaten or tied as of the end of August
In addition to the 16 all-time national/territorial records set so far in 2024 (plus five nations that tied or broke their all-time record in multiple months), 156 nations or territories have set or tied monthly all-time heat records as of the end of August 2024, for a total of 177 such records:
- Jan. (15): Mayotte, Dominica, Saba, Cocos Islands, Malta, Hong Kong, Ivory Coast, Maldives, Andorra, Portugal, Costa Rica, UK, Seychelles, Martinique, St. Barthelemy
- Feb. (18): Maldives, French Guiana, Guyana, Dominica, Curacao, St. Kitts and Nevis, Antigua and Barbuda, U.S. Virgin Islands, Belize, North Korea, Morocco, French Southern Territories, Hong Kong, Taiwan, Peru, Laos, Chad, Togo
- Mar. (24): Paraguay, Samoa, Zimbabwe, Dominica, Cameroon, Ghana, Guyana, French Guiana, Dominican Republic, Taiwan, Hong Kong, Saba, British Indian Ocean Territories, Solomon Islands, Suriname, Guatemala, Croatia, Poland, Belarus, Lithuania, Latvia, Estonia, Benin, Burkina Faso
- Apr. (28): Dominica, French Southern Territories, Costa Rica, French Polynesia, French Guiana, Guyana, Mauritania, Ivory Coast, Saba, Comoros, British Indian Ocean Territories, Mauritius, China, Slovenia, Croatia, Bosnia, Cape Verde, Nepal, Zimbabwe, Cyprus, Turkey, Niger, Jordan, Israel, Vietnam, Colombia, St. Barthelemy, Laos
- May (20): Sri Lanka, Mauritius, Tuvalu, Ivory Coast, Dominica, Niue, Brazil, Martinique, Maldives, Costa Rica, Mexico, Belize, Cayman Islands, Cuba, Saba, Cocos Islands, Niger, Kuwait, Iraq, St. Eustatius
- Jun. (25): French Southern Territories, Guatemala, Aruba, Curacao, Zimbabwe, Comoros, Grenada, St. Eustatius, North Korea, New Zealand, Dominica, Cocos Islands, Costa Rica, Mauritius, Martinique, Taiwan, Paraguay, Algeria, Turkey, St. Pierre and Miquelon, Kuwait, China, French Guiana, Guadeloupe, Malaysia
- Jul. (16): U.S. Virgin Islands, Palau, Cocos Islands, Aruba, British Indian Ocean Territories, Dominica, Saudi Arabia, Belarus, Mauritius, Maldives, Curacao, Solomon Islands, Northern Marianas, Brunei. Mozambique, French Guiana
- Aug. (10): Palau, French Southern Territories, Australia, British Indian Ocean Territories, Svalbard, Indonesia, Zimbabwe, Eswatini, Ecuador, Comoros
Two monthly national/territorial cold records beaten or tied as of the end of August
China set an all-time cold record for the month of February.
Qatar set an all-time cold record for the month of March.
Hemispherical and continental temperature records in 2024
- Highest minimum temperature ever recorded in January in Asia: 28.5°C (83.3°F) at Bangkok Klong Thoey, Thailand, Jan. 14
- Highest minimum temperature ever recorded in February in Asia: 29.1°C (84.1°F) at Diego Garcia (British Indian Territories), Feb. 18
- Highest minimum temperature ever recorded in March in South America: 31.6°C (88.9°F) at Mariscal Estigarribia, Paraguay, Mar. 17
- Highest temperature ever recorded in April in Africa: 48.5°C (119.3°F) at Kayes, Mali, Apr. 3
- Highest temperature ever recorded in May in North America: 51.1°C (124.0°F) at Gallinas, Mexico, May 9
- Highest minimum temperature ever recorded in May in the Southern Hemisphere: 29.7°C (85.5°F) at Funafuti, Tuvalu, May 21
- Highest temperature ever recorded in June in Africa: 50.9°C (123.6°F) at Assuan, Egypt, Jun. 7
- Highest minimum temperature ever recorded in June in the Southern Hemisphere: 29.3°C (84.7°F) at Funafuti, Tuvalu, Jun. 18
- Highest minimum temperature ever recorded in July in the Southern Hemisphere: 28.8°C (83.8°F) at Nukunonu, Tokelau, New Zealand territory, Jul. 16
- Highest minimum temperature ever recorded in August in the Southern Hemisphere: 29.7°C (85.5°F) at Filadelfia, Paraguay, Aug. 3
- Highest temperature ever recorded in August and in all of winter in Oceania: 41.6°C (105.8°F) at Yampi Sound, Australia, Aug. 26
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