August 2026 Was Earth’s Hottest Month Ever Measured
August 2026 was the joint-hottest month ever recorded on Earth, the European Union’s Copernicus Climate Change Service (C3S) reported on September 10, pushing global temperatures back above a critical climate threshold as a rapidly strengthening El Nino compounds the effects of human-caused warming. The finding comes as U.S. scientists confirmed the contiguous United States just sweltered through its hottest summer in more than a century of recordkeeping.
Global-average surface air temperature in August 2026 reached 16.96 C (62.53 F), Copernicus said — 0.85 C above the 1991-2020 average and the warmest August in the ERA5 dataset, which dates to 1940. The month’s average was also the joint-warmest across all calendar months, tied with July 2023. Copernicus described the 0.01 C margin over July 2023 as within the level of uncertainty, making the two months a statistical tie rather than a new outright record.
August 2026 was 1.65 C above the estimated pre-industrial baseline of 1850-1900 — the first month above 1.5 C since November 2025, and beyond the long-term threshold set by the 2015 Paris climate agreement. The eight hottest months on record have all occurred since July 2023.
The U.S. Sets a Dust Bowl-Era Benchmark
Separately, the National Oceanic and Atmospheric Administration reported that the contiguous U.S. recorded its warmest meteorological summer (June-August) in the 132-year record, averaging 74.4 F — 3.0 F above average and 0.4 F above the previous records set in 1936, during the Dust Bowl, and in 2021. It marked the first time the Lower 48 summer was hotter than the peak of the 1936 Dust Bowl.
August 2026 itself averaged 75.6 F for the contiguous U.S., the warmest August on record, with an average daytime high of 88.6 F, also a record. California, Nevada, New Mexico and Colorado each set records for their warmest August. Drought covered 59.1% of the contiguous U.S. as of September 1, up more than 10 percentage points from early August.
“This summer has really been exceptional. We’ve seen records that existed for close to 100 years be broken, in the U.S. in particular,” Samantha Burgess, Copernicus’s strategic lead for climate, told NPR and The Associated Press.
A Dual Driver: Fossil Fuels and El Nino
Scientists attribute the record heat to two factors. The dominant driver is human-caused climate change from burning coal, oil and natural gas, which raises the baseline temperature. On top of that sits a strengthening El Nino — a natural, temporary warming of parts of the Pacific that warps weather patterns worldwide.
Burgess estimated El Nino adds only one to two tenths of a degree Celsius to global temperatures, with the overwhelming remainder coming from fossil fuel emissions. “Our climate system is really operating well outside the range we would have expected just a decade ago,” she said. “We’ve transitioned from climate being very abstract … to climate impacting and disrupting our daily lives with schools closing, hospitals being overwhelmed, roads melting, train lines buckling.”
“It is now time to stop acting surprised that our warming planet keeps getting warmer. This is occurring exactly as forecast by scientists literally decades ago,” Andrew Dessler, a climate scientist at Texas A&M University, said. “The interesting question is not whether we will keep breaking heat records (we will), but whether we’re going to do anything about it.”
Friederike Otto of Imperial College London put it bluntly: “While El Nino is starting to ramp up the heat, the underlying driver remains our relentless burning of fossil fuels. Climate change makes every El Nino hotter.”
Oceans and Europe Also Break Records
The heat was not confined to the land. The average sea surface temperature for extra-polar oceans (60S-60N) in August reached 21.07 C, a record for the month, and August 22 set a record for the hottest day ever recorded in the world’s seas, at 21.11 C, Copernicus said. The monthly ocean figure tied a March 2024 all-time record for the warmest month.
Western Europe experienced its warmest summer on record, surpassing the long-standing 2003 benchmark, with severe drought reported in France, the UK, Hungary, Romania and Serbia. Major rivers including the Rhine, Danube and Vistula saw exceptionally low flows, with record-low conditions along their entire lengths. The 0.01 C margin aside, Europe’s warmth reflected a season of “exceptionally early, persistent and intense heatwaves,” Copernicus noted.
The World Meteorological Organization had warned in July that El Nino would intensify into a strong event through August-October 2026. UN Secretary-General Antonio Guterres cautioned that “El Nino is not just on our doorstep — it is inside the house and turning up the heat. And this is only a warm-up act.”
A Worsening Outlook
The record heat is part of a broader pattern with mounting consequences. The U.S. wildfire season saw 53,665 fires burn 8,397,760 acres through September 8 — the largest totals for any year since at least 2016, and about 30% above the 10-year average, according to the National Interagency Fire Center. Lake Mead and Lake Powell fell to their lowest combined levels on record.
Simon Stiell, the UN’s climate chief, told the European Parliament that this year’s summer had “hammered” infrastructure and economies, costing a likely 180 billion euros. “Until humanity stops burning colossal amount of coal, oil and gas, the pollution this causes will keep baking our planet,” he said. “This is the spiraling price of humanity’s fossil fuel addiction.”
Scientists expect the trend to continue. Zeke Hausfather of Berkeley Earth said it is “increasingly likely that 2026 ends up beating 2024 as the warmest year on record, and almost certain that 2027 beats both, potentially reaching as high as 1.8 C above preindustrial levels.” Burgess noted that some individual days could reach 2 C above mid-1800s levels.
With El Nino forecast to strengthen further, the records set in August are unlikely to stand for long.