Summer is supposed to be hot, but not like this. This year we have witnessed the hottest June, and July 2023 may be the hottest month in 120,000 years in what is shaping up to be the hottest summer in the hottest year in recorded history. Not only is the planet warming but there is a wealth of evidence suggesting this trend continues to accelerate. According to NASA, the world is getting warmer at a rate not seen in more than 10,000 years. All-time high terrestrial and sea surface temperatures set records in 2023.
June 2023 was the hottest June on record according to NASA, and it was the 47th consecutive June above historic averages, according to NOAA. June set a record for the hottest single day since 1850 and temperatures were significantly above normal on every continent on Earth. Temperatures exceeded 40°C in countries all around the world.
July 2023 has officially eclipsed July 2019 as the hottest month in recorded history. Multiple heat domes helped to shatter records breaking the highest daily average heat record three times in one week (July 3-10). On July 10th, 3.5 billion people on the planet were sweltering under the extreme heat. The sheer scope of the heat captured headlines around the world.
Temperature records fell like dominoes in July including in North America. States in the U.S. broke a slew of records for daily high heat as well as the duration of sustained heat. Phoenix, Arizona broke records with temperatures of more than 110°F (43°C) for 31 consecutive days. Austin, Texas also broke records for sustained heat when temperatures exceeded 105°F (40°C) for 10 consecutive days. Temperatures in Death Valley, California may have set a record with a temperature reading of 127.99°F (53.33°C). In the U.S. triple digit extreme heat that started in the South in June continued into August and spread to the Pacific Northwest. For much of the summer, around 100 million Americans lived under extreme heat advisories.
Even though it is winter in South America, countries like Chile and Argentina are breaking all-time high-temperature records. In some places temperatures reached triple digits, this includes parts of the Chilean Andes which saw a 102°F (38.9°C) temperature reading. In Chile and Argentina, it was 10 to 15 degrees above what is normal for this time of year, and in some places, the temperatures were hotter this winter than they were during the summer. Many high-temperature records fell including in Buenos Ares and the Argentinian town of Rivadavia.
July 2023 saw heat records fall throughout Europe including in Spain, Portugal, Greece, Italy, and France. Temperatures in July exceeded 104°F (40°C) in many areas, making the summer of 2023 hotter than Europe’s two previous record-breaking summers (2022 and 2021). The temperature in cities like Naples, Taranto, and Foggia exceeded 113°F (45°C). Madrid and Rome hit 114.8°F (46°C). In July Seville, Spain reached 116.6°F (47°C) and in August the Spanish city of Valencia broke a heat record with temperature readings of 116.24 (46.8°C). The islands of Sicily and Sardinia approached 119°F (48°C) which is among the hottest temperatures ever recorded in Europe. The highest European temperatures so far this summer were recorded on the eastern slopes of Mount Etna in Sicily, which registered readings above 122°F (50°C).
Countries across Asia have been hit by several record-breaking heat waves starting in April. Extreme heat records were broken in China, India, Vietnam, Bangladesh, Thailand, and Singapore. In July China recorded its hottest all-time temperature record with a reading of 125.96°F (52.2°C) in Xinjiang’s Sanbao Township. Beijing also set a record for four consecutive weeks with highs above 95 F (35 C). Extreme heat records were also broken in Iran, Morocco, and Algeria
Unprecedented ocean heat
Our oceans are also getting hotter. Global average sea surface temperatures hit almost 70°F (21°C) in late March and have set records throughout the Spring and Summer. Ocean temperatures have been uncharacteristically high in recent months, but they went off the charts in July when they registered the hottest average sea surface temperatures in recorded history. On July 30th the average ocean surface temperature reached an all-time high of 69.7°F (20.96°C). The highest individual ocean temperature record may have been set off the coast of Miami where temperatures reached 101.1°F (38.3°C.) (the previous highest known ocean temperature reading was 99.7°F or 37.6°C recorded in Kuwait Bay). The Mediterranean Sea broke its daily heat record with a median temperature of 83.68°F (28.71°C).
The Atlantic Ocean hit its highest temperature readings since records began in 1850. In June, parts of the North Atlantic set records for being up to 5°C warmer than normal. Extreme marine heatwaves around Ireland, Britain, and the Baltic contributed to the highest sea surface temperatures ever recorded for the month of June. NOAA reports the North Atlantic rose to a record high of 76.8°F (24.9°C) at the end of July and it is likely to get even hotter as September is historically the warmest month in the North Atlantic. Australia’s weather agency warned the Pacific and Indian Ocean Sea temperatures could be 5°F (3°C) warmer than normal by October.
Extreme weather (storms and floods)
Heat is the deadliest form of extreme weather, it also drives stronger storms and more intense floods and droughts. An Intergovernmental Panel on Climate Change (IPCC) report published earlier this year confirmed that there has been an increase in the frequency and intensity of extreme weather events since the 1950s. Storms and floods caused death, destruction, and dislocation again in 2023. In South Korea, torrential rains killed 33 people and Typhoon Doksuri forced more than 30,000 residents in Beijing China to flee. There were also intense downpours and flooding in Austria, Turkey, Kosovo, Romania, Croatia, and Slovenia. Heavy precipitation caused landslides that killed at least 21 people in Georgia.
European hail records were broken twice in the month of July. First on the 19th in Italy and Croatia, and then five days later by 19cm hailstones in the Italian town of Azzano Decimo. Throughout the summer, high heat triggered extreme weather all around the world including in the US where a spate of more than 850 storms on August 7 and 8 brought heavy rain, strong winds, hail, flooding, and tornadoes.
Heat igniting wildfires
Extreme heat is driving wildfires that are impacting every continent on Earth. They wreak death and destruction, and they exacerbate climate change by spewing billions of tons of additional GHG emissions into the atmosphere.
Wildfires were particularly pervasive in Canada this year. Prolonged heatwaves contributed to the worst wildfire season the county has ever seen. As of August 11, there were 11,038 fires still burning. These fires are known to have ravaged 13.4 million hectares (52,029 square miles or 134,756 square kilometers) or 4 percent of Canadian forests, which is twice the size of the previous worse year on record and 6 times the long-term average. Wildfires forced 160,000 Canadians to evacuate their homes.
Scorching heat ignited forest fires in Canadian provinces from coast to coast. In the East, the Canadian province of Nova Scotia recorded its largest wildfire ever which was followed by a once-in-a-hundred-year flooding event. As of August 11, there have been 519 fires in Quebec, which is 150 more than the 10-year average. So far, almost 1.5 million hectares (5,791 square miles or 14,999 square kilometers) of forest have burned. In the West, B.C. battled its worst wildfire season on record including its biggest wildfire ever.
Even the Northwest Territories (N.W.T.) in Canada’s far north is being hit with a record-setting fire season. These fires occurred as the region registered its hottest temperatures ever. Areas just south of the Arctic Circle broke records with temperature readings above 98.6°F (37°C). What makes these temperatures so exceptional is that they were warmer than readings thousands of miles to the south. As of August 12th, there were a total of 265 wildfires in N.W.T., 233 of which are still active. These fires burned 2,111,000 hectares (8150 square miles or 21,110 square kilometers).
Smoke emitted from Canadian wildfires reached all the way to Europe and caused some of the world’s worst air quality readings in large swaths of Canada and the U.S. There were also wildfires in South America, Africa, Australia, and Europe. Wildfires in Greece forced hundreds of people to flee in Athens and nineteen thousand people were forced to evacuate the isle of Rhodes. Thousands of people were evacuated in the Canary Islands and Switzerland due to extreme heat and wildfires. Wildfires continued into August in Europe and Canadian wildfires are expected to burn well into September.
The devastating wildfire in Maui was the worst disaster in Hawaii’s history. More than 2,200 buildings were destroyed, at least 100 people have died and hundreds of others are missing. Some died as they sought to escape the encroaching flames by jumping into rough seas whipped by 80 mph winds.
Red Alert: Climate change out of control
National and local governments have issued heat warnings and the European Union issued a ‘red alert’ that prompted the UN Secretary-General to say climate change is “out of control”. Heat is not anomalous in summer, what is anomalous is the intensity, duration, and scope of these heat waves. Summer heatwaves in the northern hemisphere should be expected, but not to this extent, and not alongside heatwaves in southern latitudes where temperatures are far warmer than they are supposed to be in winter.
July 2023 marked 533 consecutive months with temperatures above the 20th-century average. We have not seen a month with average temperatures in 46 years and it has been almost a half-century since the Earth has had a month with cooler-than-average temperatures. The hottest June on record followed by July, the hottest month in recorded history, led climate scientist Michael Mann to say that the summer of 2023 is “almost certainly” the hottest summer on record. According to NOAA a strengthening El Niño anomaly is expected to make the fall of 2023 and the winter of 2024 even warmer in the U.S. Canada and Europe. As reported by The Conversation, distinguished climate scholar Kevin Trenberth is among the many scientists who expect 2023 to be the warmest year to date, and 2024 to be even hotter.
Month after month, year after year, decade after decade temperature records keep falling while greenhouse gas emissions keep rising. The past seven years (2015 – 2021) have been the Earth’s hottest “by a clear margin,” according to research by the Copernicus Climate Change Service. According to the World Meteorological Organization (WMO), the last eight years are the warmest on record and 2023 will be the 9th consecutive year (2015-2023) that annual average global temperatures reach at least 1°C above pre-industrial levels. Every decade since the 70s has been warmer than the preceding decade and the period from 2020-2030 is on track to be warmer still.
In addition to deadly heat, the catastrophic impacts of the climate crisis have pervasive implications that encompass everything from food insecurity to wildfires and refugees. Extreme weather may be the most immediate and relatable manifestation of climate change. According to Joyce Kimutai, a climate scientist at the Grantham Institute, extreme weather events, “should serve as a compelling wake-up call for all of us. We need to shift the conversation to what needs to happen urgently this year.” The summer of 2023 has added more hot data to the mountain of evidence that anthropogenic climate change is driving steady upticks in terrestrial and ocean heat. This summer’s heat is yet another painfully tangible reminder of the urgent need for immediate climate action.