By Guardian-Thu 20 Feb 2025 08.00 GMTShare

Two-thirds of the world’s surface was scorched by a month or more of record-breaking heat, Guardian analysis of satellite data can reveal. In oceans and on land, from the north to the south pole, records were smashed for the monthly average temperature.

In oceans and on land, from Colombia to China, and from the north to south pole, records for the monthly average temperature were smashed time and time again last year – in some cases, by as much as 5C (9F) hotter than the previous record.

The Guardian took the average temperatures for each month in 2024, as recorded by the EU’s Copernicus Climate Change Service (C3S), and compared them with the hottest month since 1979.

Anywhere coloured in yellow through to red on the map broke a temperature record – something that scientists have warned represents “the widespread, accelerating impact of human-induced climate change”.

Records broken in September

Degrees by which previous monthly temperature record was broken in 2024

For every month from January to June 2024, the earth experienced its hottest ever average monthly temperature.

In this six-month period towns and cities across the world recorded record highs as, globally, the monthly average temperature was up by at least 0.1C compared to the last 40 years.

Between July and December 2024, the global average temperature fell just below the record highs recorded in 2023 for the same period.

But many local areas – across every continent on the planet – were still seared by record heat.

All of these broken monthly records get us to a point that, throughout the whole of 2024, 65% of the world’s surface recorded at least one month hotter than scientists had ever previously observed there.

Recent Copernicus analysis shows that 2024 was the first calendar year where the average global temperature exceeded 1.5C above its pre-industrial level.

The hottest day in recorded history was on 22 July, with the global average temperature hitting 17.16C.

Global surface air temperature

Daily averages of global mean near-surface air temperature absolute values from the ERA5 global reanalysis dataset, from January 1979.

Guardian graphic. Source: Copernicus

The carbon pollution that humans have emitted into the Earth's atmosphere has trapped sunlight and caused the planet’s temperature to rise.

On top of this, the chart shows temperatures were boosted in the first half of 2024 by the El Niño climate phenomenon. As this died out, temperatures dropped below 2023 levels – but still remained very high.

Now let’s look again at the map of 2024 temperature records and the places that saw records broken by the greatest margins.

The western part of the Hindu Kush Himalayas (HKH) saw their hottest January on record in 2024. Parts of the mountain range saw the temperature record smashed by over 5C.

Winter snow cover was low in the mountains, whose rivers supply water to a quarter of humanity.

The HKH glaciers are projected to shrink by 30-50% this century even in a best-case scenario for cutting carbon pollution.

“It is really scary,” said Arun Bhakta Shrestha, a climate scientist at Nepal’s International Centre for Integrated Mountain Development. “I have seen how glaciers have been receding, lakes have been forming … and white mountains have been turning into black rock faces.”

South America was hit by record-breaking monthly air temperatures in almost every month of 2024, but through March to June temperatures were consistently extreme in Bolivia, Peru, Colombia and the Amazonas state of Brazil.

Wildfires swept across the continent in 2024, and drought hit the Amazon. Even the Pantanal, the world’s largest wetland, went up in flames.

As China experienced its hottest summer on record, parts of the country surpassed their previous average September record by over 5C

Authorities in ‘furnace city’ Chongqing, in central China, launched almost 200 cloud-seeding rockets to artificially bring rain and cool the megacity.

Power grids across the country were strained by a surge in power demand, as people turned on their air-conditioning to seek relief from the heat.

The poles are also heating alarmingly fast. In August 2024, a large swath of Antarctica broke temperature records for that month, with temperatures up to 6.5C above the previous record. This already followed a July that broke historic records for that month.

This time of the year is midwinter for the south pole, and so the temperatures were still below zero – but some days saw temperatures reach 28C above expectations.

From August through to November, stretches of the Arctic from Canada to Russia saw their hottest months on record.

By the end of the summer melt season, in September, the extent of sea ice was at the sixth-lowest level that scientists had ever seen.

They expect the Arctic to see its first ice-free September within the next decade.

In every month of 2024, the the oceans experienced record surface air temperatures. The Atlantic was especially hot in the first half of the year. Parts of the Pacific and Indian oceans broke monthly air temperature records by over 1C for every month.

What that means to people is “an explosion of extreme events of all sorts,” said Regina Rodrigues, an ocean scientist at Brazil’s Federal University of Santa Catarina.

Hot air can hold more moisture, allowing storms to unleash more rain, while a hot ocean has more energy to feed hurricanes and cyclones as they release water vapour and heat. “It's almost as if it were boiling. What a warmer ocean does is cause rapid intensification,” said Rodrigues.

Overall, global warming is caused by burning fossil fuels. Experts warn that continuing to do so will lead to more death, disease and destruction.

The Paris agreement set a target of limiting global warming to 1.5C by the end of the century. While 2024 surpassed this level, the target is measured over decades, so a single year above that level does not mean the target has been missed.

Still, current policies put the world on track for 2.7C of global heating, and experts warn the climate emergency continues to get worse with every fraction of a degree that temperatures rise. Every year in the past decade has been one of the 10 hottest, in records that go back to 1850.

C3S senior scientist Julien Nicolas said: “These findings highlight the unprecedented conditions of 2024 and the widespread, accelerating impact of human-induced climate change. As the planet continues to warm, more records are likely to be broken in many parts of the world, exposing larger populations to extreme heat, placing greater strain on the environment and ecosystems, and increasing the risk of profound and irreversible changes to the climate.”

The Guardian analysis is based on air temperature two metres above the ground or sea. The monthly figures are based on an average of the daily figures, which themselves are an average of the hourly temperatures from Copernicus.

These hourly snapshots are calculated by state-of-the-art reanalysis models, which combine billions of readings from satellites, ships, planes and weather stations. They are more accurate in populated parts of the planet than in remote regions with few direct observation sites.

“These analyses are consistent with what is expected given the very large warming so far, and the particularly extreme conditions this year,” said Sonia Seneviratne, a climate scientist at ETH Zurich and vice-chair of the physical science working group of the Intergovernmental Panel on Climate Change (IPCC).

“If we don’t manage to decrease the burning of fossil fuels and reduce the global emissions of CO2 fast, these extreme temperatures will continue to become even more extreme and frequent,” she said. “Some regions could become uninhabitable. The last IPCC report has highlighted that we are starting to reach some limits to adaptation under the current level of global warming.”