Earth just logged its hottest August on record, and September is running warmer still

Global temperature data for August 2026 shows the month tied as the hottest August ever measured, matching a record set just three years earlier, and early readings for September indicate the heat has not let up. The figures come from the European Union’s Copernicus Climate Change Service, which tracks global temperature using satellite and ground-based data going back to the mid-1800s.

How August 2026 compares with prior records

Copernicus measured a global average surface air temperature of 16.96 degrees Celsius for August 2026, putting the month 0.85 degrees above the 1991-2020 average used as a baseline for comparison and 1.65 degrees above estimated pre-industrial levels from the late 1800s. That placed August 2026 in a statistical tie with July 2023 for the hottest month in the more than 175-year instrument record, with the difference between the two months smaller than a hundredth of a degree.

The monthly figure also marked the first time the global average has crossed 1.5 degrees above pre-industrial levels since November 2025, a threshold widely referenced in international climate agreements as a marker of how much warming the planet has accumulated.

Because the instrument record only extends back to the mid-1800s, comparisons with earlier climate periods rely on indirect indicators such as tree rings, ice cores, and ocean sediment layers rather than direct thermometer readings. Those proxy records suggest recent decades have been unusually warm even when measured against a much longer span of Earth’s climate history, adding context to how unusual a single record month like August 2026 really is.

Oceans set their own record alongside the air

Sea surface temperatures outside the polar regions averaged 21.07 degrees Celsius in August, edging past the previous record of 20.98 degrees set in 2023. Warmer oceans matter beyond the immediate temperature reading because they hold onto heat far longer than the atmosphere does, feeding energy into storms and slowing how quickly regional weather patterns can cool once a heat spike passes.

The same warm-ocean pattern has been linked in past years to more intense tropical cyclones, since storms draw much of their energy from warm surface water, though attributing any single storm season to one month’s ocean temperature requires more analysis than the monthly figures alone can provide.

That heat-retention property is one reason scientists tend to watch ocean temperature records as closely as air temperature records, since a warmer ocean surface can continue influencing weather patterns for months after the air temperature that helped create it has already cooled. Warmer surface water also affects marine ecosystems directly, altering the range and behavior of fish and other species that depend on specific temperature bands to feed and reproduce.

What drove the August spike

Copernicus attributed the record largely to a combination of long-running greenhouse gas accumulation and a strong El Niño pattern in the tropical Pacific, which tends to release stored ocean heat into the atmosphere and push global averages higher for a year or more after it develops. United Nations climate reporting earlier in the year had already flagged 2026 as a strong candidate for one of the warmest years on record given the trajectory of the same El Niño event.

El Niño events develop when trade winds weaken across the tropical Pacific, allowing warm water that is normally pushed toward Asia to spread back toward the Americas, a shift that changes weather patterns across much of the globe for a year or more at a time. Because El Niño’s warming effect on global temperatures tends to peak roughly a year after the event itself develops, scientists monitoring the current pattern have said global average temperatures could remain elevated for some time even if the underlying ocean pattern begins to fade.

Visible effects across western Europe

The record month coincided with drought conditions, wildfire activity, and unusually low river flows across parts of western Europe, effects consistent with how a warmer atmosphere tends to intensify both ends of the water cycle — worsening dry spells in already-dry regions while feeding heavier rainfall elsewhere. Reduced river flow in particular has downstream effects on agriculture, shipping, and power generation in areas that rely on rivers for cooling water or hydroelectric output.

Southern Europe in particular has dealt with repeated summer heat waves over the past several years, and persistent low river flows have already prompted water-use restrictions in some regions, illustrating how a single record month sits inside a longer run of compounding dry conditions rather than as an isolated event.

Early September data points to more of the same

Preliminary government weather data for the opening weeks of September 2026 shows the month tracking well above its own historical average, consistent with a year in which nearly every month with published data has ranked among the five warmest on record for that specific month. A final, confirmed reading for September is not expected until early October, when Copernicus and other tracking agencies release their standard monthly analysis, but the early trend has been consistent enough that scientists have not signaled any expectation of a sharp reversal.

Meteorologists caution that early-month data can shift as more weather stations report and as revisions are applied, which is why agencies wait for a complete month of readings before issuing an official ranking. Even so, forecasters tracking the pattern have said the odds currently favor September 2026 finishing among the warmer Septembers on record rather than reverting sharply toward a cooler historical average.

Why a single record month matters beyond one number

Individual monthly records draw attention on their own, but scientists who track these figures tend to emphasize the broader trend line more than any single month, since natural variability from year to year can push any given month up or down independent of the underlying warming trend. What has changed in recent years is how consistently new records are being set at all, with the same handful of years — 2023, 2024, and now 2026 — repeatedly trading places at the top of the ranked list rather than older records standing for a decade or more.

That repetition has led some climate scientists to describe the current run of records less as a series of isolated extreme events and more as evidence that the range of what counts as a typical month has itself shifted upward. Tracking how often each year contributes a new record, rather than focusing on any single month in isolation, is part of how researchers distinguish a genuine shift in the underlying climate from ordinary year-to-year variability.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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