Southwest Europe wilted through a third summer heatwave, fires tore through Spain and Portugal, while many parts of Asia experienced above-average temperatures during a scorching month that neared record highs.

The world's oceans, which help regulate Earth's climate by absorbing excess heat from the atmosphere, were also close to record high temperatures for the month. Hotter seas are linked to worsening weather extremes.

"With the world's (oceans) also remaining unusually warm, these events underline not only the urgency of reducing emissions but also the critical need to adapt to more frequent and intense climate extremes," said Samantha Burgess, strategic lead for climate at the EU's Copernicus Climate Change Service.

Global temperatures have been stoked ever higher by humanity's emissions of planet-heating gases, largely from fossil fuels burned on a massive scale since the industrial revolution.

Copernicus takes these measurements using billions of satellite and weather readings, both on land and at sea, and their data extends back to 1940.

The average temperature globally for August was 1.29 degrees Celsius above pre-industrial times, marginally cooler than the monthly record set in 2023 and tied with 2024.

Such incremental rises may appear small, but scientists warn that is already destabilising the climate and making storms, floods and other disasters fiercer and and more frequent.

In its monthly bulletin, Copernicus said that western Europe experienced the continent's most pronounced above-average temperatures, with southwest France and the Iberian Peninsula particularly affected.

Spain suffered a 16-day heatwave that caused more than 1,100 deaths, according to the Carlos III Health Institute. Wildfires in Spain and Portugal forced thousands to evacuate.

Last week, scientists said human-caused climate change made the hot, dry and windy conditions that fanned the blazes 40 times more likely.

Outside Europe, temperatures were most above average across Siberia, parts of Antarctica, China, the Korean Peninsula, Japan and the Middle East.

Record-breaking ocean temperatures were measured in the North Atlantic to the west of France and the United Kingdom in August. Across the Mediterranean the picture was mixed and less extreme than 2024.

The UK, Japan and South Korea sweltered this year through the hottest summers since each country began keeping records, their respective weather agencies announced earlier this month.