Special Report

How 2023 Compares To The Hottest Summers Over Last 50 Years

Ralph Freso / Getty Images

The torrid summer of 2023 is drawing to a close, and according to the European Union-funded Copernicus Climate Change Service, the planet had its hottest three months ever. It was the hottest August on record (global mean surface air temperature), and the second-hottest month ever after July 2023. (Here are the hottest inhabited places on Earth.)

To identify the hottest summers on Earth over the last 50 years, 24/7 Wall st. reviewed data on the average temperature in August for each year between 1940 and Aug. 31, 2023 from the Copernicus Climate Change Service. The anomaly — the degree by which each average temperature in August differs from historically normal temperatures between 1991 and 2020 — also came from the Copernicus Climate Change Service. 

The June-to-August season for 2023 was the warmest on record worldwide, with an average temperature of 16.77°C (62.1 Fahrenheit), 0.66°C above average. The hottest 10 summers have all occurred over the past 10 years.

The Copernicus group said August is estimated to have been around 1.5°C warmer than the pre-industrial average for 1850-1900. The 1.5°C mark is considered a critical threshold and once crossed, the effects of climate change are expected to become more severe. August recorded the highest global monthly average sea-surface temperatures of 20.98°C, or 69.7 Fahrenheit. The period from January to August 2023 is the second warmest on record after 2016, when a warming El Niño event occurred.

“What we are observing, not only new extremes but the persistence of these record-breaking conditions, and the impacts these have on both people and planet, are a clear consequence of the warming of the climate system,” said Carlo Buontempo, director of the Copernicus Climate Change Service, European Centre for Medium-Range Weather Forecasts, in a statement. (These are the 25 worst cities to live as global warming gets worse.)

In the United States, more than 6,500 daily heat records have so far broken during the scorching summer. As of Sept. 6, Phoenix had 52 days of highs of 110 degrees or above. Cities such as Houston; Chicago; Lincoln, Nebraska; Wichita, Kansas; New Orleans; Denver; and Portland, Oregon, to name a few, all reported daily heat records.  

Click here to see the hottest boreal summers over the last 50 years.

Pictorial Parade / Getty Images

1974
> Avg temp in August: 59.8°F – #75 highest on 1940-2023 record
> Size of anomaly: -1.2°F from 1991-2020 normal – #29 coldest difference

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Archive Photos / Getty Images

1975
> Avg temp in August: 59.6°F – #81 highest on 1940-2023 record
> Size of anomaly: -1.4°F from 1991-2020 normal – #31 coldest difference

Keystone / Getty Images

1976
> Avg temp in August: 59.7°F – #78 highest on 1940-2023 record
> Size of anomaly: -1.3°F from 1991-2020 normal – #30 coldest difference

Michael Ochs Archives / Getty Images

1977
> Avg temp in August: 60.2°F – #41 highest on 1940-2023 record
> Size of anomaly: -0.8°F from 1991-2020 normal – #22 coldest difference

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Space Frontiers / Getty Images

1978
> Avg temp in August: 59.9°F – #69 highest on 1940-2023 record
> Size of anomaly: -1.1°F from 1991-2020 normal – #28 coldest difference

Tony Duffy / Getty Images

1979
> Avg temp in August: 60.2°F – #45 highest on 1940-2023 record
> Size of anomaly: -0.8°F from 1991-2020 normal – #25 coldest difference

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FPG / Getty Images

1980
> Avg temp in August: 60.5°F – #35 highest on 1940-2023 record
> Size of anomaly: -0.5°F from 1991-2020 normal – #16 coldest difference

Gene Forte / Getty Images

1981
> Avg temp in August: 60.6°F – #34 highest on 1940-2023 record
> Size of anomaly: -0.4°F from 1991-2020 normal – #15 coldest difference

Hulton Archive / Getty Images

1982
> Avg temp in August: 60.3°F – #40 highest on 1940-2023 record
> Size of anomaly: -0.7°F from 1991-2020 normal – #21 coldest difference

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Tony Duffy / Getty Images

1983
> Avg temp in August: 60.5°F – #36 highest on 1940-2023 record
> Size of anomaly: -0.5°F from 1991-2020 normal – #17 coldest difference

Michael Ochs Archives / Getty Images

1984
> Avg temp in August: 60.1°F – #48 highest on 1940-2023 record
> Size of anomaly: -0.9°F from 1991-2020 normal – #27 coldest difference

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Space Frontiers / Getty Images

1985
> Avg temp in August: 60.2°F – #47 highest on 1940-2023 record
> Size of anomaly: -0.8°F from 1991-2020 normal – #26 coldest difference

Getty Images / Staff

1986
> Avg temp in August: 60.2°F – #45 highest on 1940-2023 record
> Size of anomaly: -0.8°F from 1991-2020 normal – #24 coldest difference

Rick Stewart / Getty Images

1987
> Avg temp in August: 60.7°F – #29 highest on 1940-2023 record
> Size of anomaly: -0.3°F from 1991-2020 normal – #10 coldest difference

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Getty Images / Staff

1988
> Avg temp in August: 60.7°F – #28 highest on 1940-2023 record
> Size of anomaly: -0.3°F from 1991-2020 normal – #9 coldest difference

Pascal Rondeau / Getty Images

1989
> Avg temp in August: 60.4°F – #38 highest on 1940-2023 record
> Size of anomaly: -0.6°F from 1991-2020 normal – #19 coldest difference

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Space Frontiers / Getty Images

1990
> Avg temp in August: 60.7°F – #27 highest on 1940-2023 record
> Size of anomaly: -0.3°F from 1991-2020 normal – #8 coldest difference

Public Domain / Wikimedia Commons

1991
> Avg temp in August: 60.9°F – #21 highest on 1940-2023 record
> Size of anomaly: -0.1°F from 1991-2020 normal – #3 coldest difference

Public Domain / Wikimedia Commons

1992
> Avg temp in August: 60.2°F – #41 highest on 1940-2023 record
> Size of anomaly: -0.8°F from 1991-2020 normal – #22 coldest difference

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Public Domain / Wikimedia Commons

1993
> Avg temp in August: 60.4°F – #39 highest on 1940-2023 record
> Size of anomaly: -0.6°F from 1991-2020 normal – #20 coldest difference

Phil Cole / Getty Images

1994
> Avg temp in August: 60.4°F – #37 highest on 1940-2023 record
> Size of anomaly: -0.6°F from 1991-2020 normal – #18 coldest difference

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Public Domain / Wikimedia Commons

1995
> Avg temp in August: 60.8°F – #24 highest on 1940-2023 record
> Size of anomaly: -0.2°F from 1991-2020 normal – #6 coldest difference

Jeff J Mitchell / Getty Images

1996
> Avg temp in August: 60.6°F – #31 highest on 1940-2023 record
> Size of anomaly: -0.4°F from 1991-2020 normal – #12 coldest difference

Doug Pensinger / Getty Images

1997
> Avg temp in August: 60.8°F – #26 highest on 1940-2023 record
> Size of anomaly: -0.2°F from 1991-2020 normal – #7 coldest difference

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Space Frontiers / Getty Images

1998
> Avg temp in August: 61.3°F – #10 highest on 1940-2023 record
> Size of anomaly: 0.3°F from 1991-2020 normal – ##N/A warmest difference

USAF / Getty Images

1999
> Avg temp in August: 60.6°F – #32 highest on 1940-2023 record
> Size of anomaly: -0.4°F from 1991-2020 normal – #13 coldest difference

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NASA / Getty Images

2000
> Avg temp in August: 60.6°F – #32 highest on 1940-2023 record
> Size of anomaly: -0.4°F from 1991-2020 normal – #13 coldest difference

Mark Wilson / Getty Images

2001
> Avg temp in August: 60.9°F – #23 highest on 1940-2023 record
> Size of anomaly: -0.1°F from 1991-2020 normal – #5 coldest difference

Mark Wilson / Getty Images

2002
> Avg temp in August: 61.0°F – #19 highest on 1940-2023 record
> Size of anomaly: 0.0°F from 1991-2020 normal – ##N/A warmest difference

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Scott Barbour / Getty Images

2003
> Avg temp in August: 60.9°F – #21 highest on 1940-2023 record
> Size of anomaly: -0.1°F from 1991-2020 normal – #3 coldest difference

Chris Jackson / Getty Images

2004
> Avg temp in August: 60.7°F – #29 highest on 1940-2023 record
> Size of anomaly: -0.3°F from 1991-2020 normal – #10 coldest difference

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2005
> Avg temp in August: 61.1°F – #14 highest on 1940-2023 record
> Size of anomaly: 0.1°F from 1991-2020 normal – #13 warmest difference

Wathiq Khuzaie / Getty Images

2006
> Avg temp in August: 61.1°F – #17 highest on 1940-2023 record
> Size of anomaly: 0.1°F from 1991-2020 normal – #16 warmest difference

David Paul Morris / Getty Images

2007
> Avg temp in August: 61.0°F – #20 highest on 1940-2023 record
> Size of anomaly: 0.0°F from 1991-2020 normal – ##N/A coldest difference

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Spencer Platt / Getty Images

2008
> Avg temp in August: 60.8°F – #24 highest on 1940-2023 record
> Size of anomaly: -0.2°F from 1991-2020 normal – #6 coldest difference

Alex Wong / Getty Images

2009
> Avg temp in August: 61.1°F – #14 highest on 1940-2023 record
> Size of anomaly: 0.1°F from 1991-2020 normal – #13 warmest difference

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Chris Graythen / Getty Images

2010
> Avg temp in August: 61.1°F – #14 highest on 1940-2023 record
> Size of anomaly: 0.1°F from 1991-2020 normal – #13 warmest difference

Majid Saeedi / Getty Images

2011
> Avg temp in August: 61.2°F – #11 highest on 1940-2023 record
> Size of anomaly: 0.2°F from 1991-2020 normal – #10 warmest difference

Peter Macdiarmid / Getty Images

2012
> Avg temp in August: 61.1°F – #13 highest on 1940-2023 record
> Size of anomaly: 0.1°F from 1991-2020 normal – #12 warmest difference

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Michael Buckner / Getty Images

2013
> Avg temp in August: 61.1°F – #18 highest on 1940-2023 record
> Size of anomaly: 0.1°F from 1991-2020 normal – #17 warmest difference

Sean Gallup / Getty Images

2014
> Avg temp in August: 61.2°F – #11 highest on 1940-2023 record
> Size of anomaly: 0.2°F from 1991-2020 normal – #10 warmest difference

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NASA / Getty Images

2015
> Avg temp in August: 61.3°F – #9 highest on 1940-2023 record
> Size of anomaly: 0.3°F from 1991-2020 normal – #9 warmest difference

Scott Olson / Getty Images

2016
> Avg temp in August: 61.6°F – #3 highest on 1940-2023 record
> Size of anomaly: 0.6°F from 1991-2020 normal – #3 warmest difference

NASA / Getty Images

2017
> Avg temp in August: 61.4°F – #7 highest on 1940-2023 record
> Size of anomaly: 0.4°F from 1991-2020 normal – #7 warmest difference

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Justin Sullivan / Getty Images

2018
> Avg temp in August: 61.4°F – #8 highest on 1940-2023 record
> Size of anomaly: 0.4°F from 1991-2020 normal – #8 warmest difference

Anthony Kwan / Getty Images

2019
> Avg temp in August: 61.7°F – #2 highest on 1940-2023 record
> Size of anomaly: 0.7°F from 1991-2020 normal – #2 warmest difference

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flyparade / Getty Images

2020
> Avg temp in August: 61.6°F – #5 highest on 1940-2023 record
> Size of anomaly: 0.6°F from 1991-2020 normal – #5 warmest difference

Alex Wong / Getty Images

2021
> Avg temp in August: 61.5°F – #6 highest on 1940-2023 record
> Size of anomaly: 0.5°F from 1991-2020 normal – #6 warmest difference

romrodinka / Getty Images

2022
> Avg temp in August: 61.6°F – #4 highest on 1940-2023 record
> Size of anomaly: 0.6°F from 1991-2020 normal – #4 warmest difference

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2023
> Avg temp in August: 62.2°F – #1 highest on 1940-2023 record
> Size of anomaly: 1.2°F from 1991-2020 normal – #1 warmest difference

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