2025 on course to have been the joint-second-warmest year since records began.

With temperature measurements now available for eleven of twelve months, 2025 is currently tied with 2023 as the second-warmest year on record, with 2024 remaining the warmest recorded year, according to a press release issued by the European Copernicus Climate Change Service on 9 December 2025. November 2025 was the third warmest November on record (behind 2024 and 2023), with notably-warmer-than-average temperatures particularly prevalent over Canada and the Arctic Ocean. The month also saw a number of extreme weather events, including a series of tropical cyclones across Southeast Asia, which caused catastrophic flooding over a wide area.

Annual global surface air temperature anomalies (°C) relative to the 1850–1900 pre-industrial reference from 1967 to 2025. The value for 2025 is based on data for January to November. Copernicus Climate Change Service.

November 2025 was the third warmest November on record, with an average surface air temperature of 14.02°C, which was 0.65°C warmer than the November average for the period 1991-2020. It was, however, 0.20°C cooler than the average for the warmest November on record, in 2023, and 0.08°C cooler than the average for the second-warmest November on record, 2024. November 2025 was also 1.54°C above the estimated average temperature for the period 1850-1900, taken as the pre-industrial reference point. It was the second consecutive month to be more than 1.50°C above this reference, and the sixth such month in 2025, the figure having previously been exceeded in January, February, March, April, and October. It is now almost certain that 2025 will be one of the three warmest years since records began, unlikely to be warmer than 2024, but closely tied with 2023 to be the second-warmest year. It is possible that the average temperature for 2025 will not be 1.5°C above the pre-industrial reference, it is now almost certain that the average for the three year period 2023-2025 will be, the first recorded three-year period to be this warm.

Monthly global surface air temperature anomalies (°C) relative to the 1850–1900 pre-industrial reference period from January 1940 to November 2025, plotted as time series for each year. The year 2025 as well as the two warmest calendar years are shown in colour: 2025 in dark red, 2024 in orange, and 2023 in yellow. All other years are shown with thin grey lines. Copernicus Climate Change Service.

The global average temperature for the period September-November 2025 was the third highest on record, 0.67°C above the average for period 1991-2020, with only the years 2023 and 2024 having been warmer. The temperature was particularly warm over northern Canada, the Arctic Ocean, and Antarctica, but cooler than average over northeastern Russia.

The average land temperature over Europe was 5.74°C, 1.38°C above the average for the period 1991-2020, and making it the fifth-warmest November ever recorded in Europe. Temperatures were furthest above average over Eastern Europe, European Russia, the Balkan Peninsula, and Turkey. However, below average temperatures were encountered present over northern Sweden, Finland, Iceland, southern Germany, and northern Italy. Beyond Europe, temperatures were particularly high over both polar regions, northeastern Canada, the Canadian archipelago, the United States, the Arctic Ocean, and East Antarctica. Temperatures were notably below average over Siberia and northeastern Russia.

The period September-November 2025 was the fourth warmest such interval recorded in Europe, 1.06°C above the average for the period 1991-2020. Over this period, temperatures were notably warmer over Fennoscandia and European Russia, but near-average over Western and Central Europe.

The average sea surface temperature between 60° north and 60° south was 20.42°C in November 2025, making it the fourth warmest November measured by this metric, and 0.29°C cooler than the warmest recorded November, in 2023. Sea surface temperatures were particularly warm over the North Pacific, with record high temperatures recorded in the western North Pacific. However, temperatures over the central and eastern equatorial Pacific were near, or slightly below, average, probably due to a developing weak La Niña system. Record breaking temperatures were also recorded over the Norwegian Sea and the Coral Sea off the east coast of Australia.

Surface air temperature anomaly for November 2025 relative to the November average for the period 1991-2020. Copernicus Climate Change Service.

November was wetter than average across the UK, Ireland, Portugal, Spain, northwestern Russia, and much of the Balkan Peninsula, particularly Albania and Greece. The wet conditions over Western Europe were partly fuelled by Atlantic Storm Claudia. At the same time, Iceland, southern Spain, northern Italy, central Germany and Sweden, were drier than average, and conditions in southwestern Russia, Ukraine, and Turkey were close to drought level. Outside Europe, wetter than average conditions affected  the southwest USA, parts of northern Canada, northwestern Russia, Taiwan, southern Africa, Madagascar, and coastal regions of Australia. Flooding and related events, brought on by a combination of several tropical cyclones and a particularly heavy monsoon season, killed over 1100 people across South and Southeast Asia. At the same time, northern Mexico, the southeastern USA, much of western and central Asia, and southern Brazil had drier than normal conditions.

The period September-November 2025 was wetter than average across the UK, Ireland, most of Scandinavia, western Iberia and the southeastern part of Spain, and Central Europe. Romania and the Balkan Peninsula were drier than average in September, but wetter than average on October and November. Drier than average conditions were present over northern Italy, southern France, the larger  islands of the Mediterranean, and much of Eastern Europe including Turkey and western Russia. Much of Iberia remained dry, with persistently low soil humidity. Iceland began this period with dryer than average conditions, but ended with wetter than average conditions. 

Outside Europe, wetter than average conditions were prevalent from September to November over the western United States, Alaska, northwestern Mexico, the Korean Peninsula, eastern China, central Asia, southern Africa, Madagascar, the northern coast of Australia, and New Zealand. At the same time, drier than average conditions affected the southern and eastern United States, much of western Asia, southern Brazil and southeastern Australia. 

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Tapanuli Orangutans brought closer to extinction by Cyclone Senyar.

The Tapanuli Orangutan, Pongo tapanuliensis, is thought to have moved significantly closer to extinction after Cyclone Senyar passed across Sumatra on 25 November 2025. The species, which was only discovered in 2017, is considered to be the world's rarest Ape, with a population of about 800 all living within an area of less than 1000 km² in North Sumatra. It is considered to be Critically Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species.

A male Tapanuli Orangutan, Pongo tapanuliensis. Maxime Aliaga/Sumatran Orangutan Conservation Program.

Cyclone Senyar caused more than 1000 mm of rain to fall in a day in parts of North Sumatra, triggering a series of catastrophic floods and landslides which killed over a thousand people on the island. The three districts where the species is found, North, Central, and South Tapanuli, have been particularly badly hit, with satellite images showing that between 48 and 72 km² of the forest inhabited by Tapanuli Orangutans has been destroyed, according to Erik Meijaard of Borneo Futures, who has been studying the storm's impact on the Apes. This could potentially equate to between 33 and 55 Orangutans, or between 6.2% and 10.5% of the total population.

So far, only a single dead Orangutan has been found, leading to the possibility that the Apes may have been able to escape the area before the worst of the event, although this is not typical Orangutan behaviour; they usually seek the nearest shelter and attempt to wait out large storms. Even should this have been the case, the storm appears to have destroyed large areas of their native habitat, including food sources, which makes it likely that more Orangutans will be lost in the near future. 

A dead Tapanuli Orangutan found amid storm debris in the village of Pulo Pakkat, North Sumatra, following the passage of Cyclone Senyar. Decky Chandra/The Guardian.

The population was already considered to be threatened by the expansion of mining, hydropower projects and palm oil plantations, within their habitat, as well as a rapidly changing environment, with global warning already having led to an increase in rainfall of between 28 and 160% across Sumatra. One possible benefit to the Orangutans is that the Indonesian government has ordered a halt to all new development projects in the Tapanuli area, pending a survey of the region, which may lead to their gaining some extra long-term protection. The government has also indicated its support for forest restoration projects in the region, which could lead to an increase in the available habitat for the Apes.

The storm is also reported to have completely destroyed the Ketambe Research Station, within the Gunung Leuser National Park in Aceh Province, which was the first specialist Orangutan research centre in the world, opened in 1971 by Dutch primatologist Herman Rijksen, and a leading centre for research into the Sumatran Orangutan, Pongo abelii, which is also considered to be Critically Endangered.

Damage caused to the Ketambe Research Station, within the Gunung Leuser National Park by Cyclone Senyar. American Association of Zookeepers. 

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Number of dead in Sri Lanka following Cyclone Ditwah has now reached 619.

The number of people known to have died after Cyclone Ditwah made landfall in Sri Lanka on 28 November 2025 has reached 219, making the storm the worst natural disaster to befall the nation since the Boxing Day Tsunami of 2004. A further 209 people are still recorded as missing since the storm, with 18 people listed as having been injured. About 2 million people (almost 10% of the population) are thought to have been affected in some way by the storm, with 4071 homes destroyed and 71 121 damaged by flooding and landslides, as has much of the island's infrastructure and agricultural land. Authorities in Sri Lanka are warning that there is still a high risk of landslides, as monsoon rains fall onto already soaked hillside soils. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.

Flooding in the Gampaha District of Colombo, Sri Lanka, following the passage of Cyclone Ditwah. Incept Change/UNICEF. 

Cyclone Ditwah was first detected as a tropical depression off the south coast of Sri Lanka by the Indian Meteorological Department on 26 November 2025. This depression increased in strength, becoming first a deep depression and then a cyclonic storm of 27 November. It crossed over Sri Lanka on the night of 28-29 November, bringing catastrophic levels of rainfall, then moved out over the Bay of Bengal. The storm continued to move northwatds along the Coromandel Coast, in the process bringing more flooding to the states of Tamil Nadu and Puducherry, which led to three Human and 149 Cattle deaths, as well as flooding much farmland, and damaging or destroying 234 homes. The storm weakened as it moved northward, eventually making landfall in Tamil Nadu as a low pressure system on 3 December.

Flood damage beside the Mahaweli River in Kandy, Sri Lanka, following the passage of Cyclone Ditwah. Reuters.

Tropical storms are caused by the warming effect of the Sun over tropical seas. As the air warms it expands, causing a drop in air pressure, and rises, causing air from outside the area to rush in to replace it. If this happens over a sufficiently wide area, then the inrushing winds will be affected by centrifugal forces caused by the Earth's rotation (the Coriolis effect). This means that winds will be deflected clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere, eventually creating a large, rotating Tropical Storm. They have different names in different parts of the world, with those in the Indian Ocean being referred to as cylcones.

The structure of a tropical cyclone. Wikimedia Commons.

Despite the obvious danger of winds of this speed, which can physically blow people, and other large objects, away as well as damaging buildings and uprooting trees, the real danger from these storms comes from the flooding they bring. Each drop millibar drop in air-pressure leads to an approximate 1 cm rise in sea level, with big tropical storms capable of causing a storm surge of several meters. This is always accompanied by heavy rainfall, since warm air over the ocean leads to evaporation of sea water, which is then carried with the storm. These combined often lead to catastrophic flooding in areas hit by tropical storms. 

The formation and impact of a storm surge. eSchoolToday.

Cyclone Ditwah is not considered to be a large storm, but has caused extensive damage due to the large volumes of water it dropped onto Sri Lanka. It has been estimated that the cost of repairing the infrastructure damage caused by the storm will be about US$7 billion, coupled with a loss of income from the destruction of the agricultural and tourism sectors. Sri Lanka had a gross domestic product of about US$99 billion in 2024, but suffers from high levels of government debt. In 2023 the country was obliged to borrow US$3 billion from the International Monetary Fund to help with debt servicing, after a period of economic contraction in 2022 which led inflation to reach 57%. 

Sri Lanka is considered to have met the first United Nations' Millennium Development Goal, halving extreme poverty between 1990 and 2015, but 12% of the country is still considered to be living below the extreme poverty line, and 53% below the poverty line. While the country has made progress on growing its economy and lifting its people out of poverty, climatic events such as Cyclone Ditwah can set progress back significantly, and are predicted to become more common as the climate warms. Countries in the Global South are predicted to be particularly badly impacted by effects of global warming, despite having done little to cause the crisis; Sri Lanka is considered to have produced about 0.03% of global greenhouse gas emissions since the onset of the Industrial Revolution.

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Over 1000 people thought to have died in Indonesia, Malaysia, and Thailand as a result of Cyclone Senyar.

At least 1000 people are thought to have died, with more than 2700 more known to have been injured and more than 500 still missing after Cyclone Senyar swept across Sumatra and Peninsula Malaysia on 26-28 November 2025. The storm formed as a tropical depression in the Strait of Malacca on 22 November 2025, intensifying to become a tropical cyclone before making landfall on the northern part of Sumatra at about midnight on 26 November 2025. The storm moved southwards along the coast of North Sumatra, before sweeping back across the Strait of Malacca to make landfall on Peninsula Malaysia on 27 November. On 28 November the storm swept out over the South China Sea, where it dissipated several days later without making landfall again.

Flooding in Padangsidimpuan, North Sumatra on 26 November 2025. Badan Nasional Penanggulangan Bencana/Wikimedia Commons.

The passage of Cyclone Senyar resulted in at least 753 deaths on Sumatra, with a further 2600 injured and 526 people still missing, largely as a result of flooding and landslides. Over 1.2 million people on the island have been displaced because of the storm with about 3.3 million affected in some way, across the provinces of North Sumatra, West Sumatra, and Aceh. The storm is reported to have destroyed 3600 homes, and damaged a further 5800, along with 344 bridges and 324 schools.

A woman clearing mud from a house in the town of Meureudu in Aceh Province, Sumatra, following the passage of Cyclone Senyer. Hotli Simanjuntak/EPA.

The storm caused less damage in Peninsula Malaysia, where people had more time to prepare, with three fatalities, and 34 000 people evacuated from high-risk areas ahead of the storm. However, in neighbouring part of southern Thailand, flooding associated with the storm killed at least 267 people, with most of the fatalities occurring in Songkhla Province, according to government figures; although some sources have accused the government of downplaying the size of the disaster, with suggestions that more than 1000 people may have died in Songkhla Province alone. In addition, at least 102 people were injured, with two homes destroyed and 1074 damaged, along with 228 roads, 12 bridges, 41 schools and 38 temples. The city of Hat Yai in Sonhkla Province received 372 mm of rain on 21 November, more than is typical for the entire month of November, and more rain than has fallen on the city in a single day in 300 years of records.

Flooding in Songkhla Province, southern Thailand, on 26 November 2025. AP.

Tropical storms, called Cyclones in the Indian Ocean and South Pacific, are caused by solar energy heating the air above the oceans, which causes the air to rise leading to an inrush of air. If this happens over a large enough area the inrushing air will start to circulate, as the rotation of the Earth causes the winds closer to the equator to move eastwards compared to those further away (the Coriolis Effect). This leads to tropical storms rotating clockwise in the southern hemisphere and anticlockwise in the northern hemisphere. These storms tend to grow in strength as they move across the ocean and lose it as they pass over land (this is not completely true: many tropical storms peter out without reaching land due to wider atmospheric patterns), since the land tends to absorb solar energy while the sea reflects it.

The formation of a tropical cyclone. Natural Disaster Management.

Despite the obvious danger of winds of this speed, which can physically blow people, and other large objects, away as well as damaging buildings and uprooting trees, the real danger from these storms comes from the flooding they bring. Each drop millibar drop in air-pressure leads to an approximate 1 cm rise in sea level, with big tropical storms capable of causing a storm surge of several meters. This is always accompanied by heavy rainfall, since warm air over the ocean leads to evaporation of sea water, which is then carried with the storm. These combined often lead to catastrophic flooding in areas hit by tropical storms. 

The formation and impact of a storm surge. eSchoolToday.

However, Cyclone Senyar is unusual in that it formed in a part of the world not usually prone to tropical storms; it is only the first such storm ever to form in the Strait of Malacca, and the second to cross these waters, after Typhoon Vamei, which formed in the South China Sea in 2001, and crossed Peninsula Malaysia from east to west. This is because the Strait of Malacca is close to the equator, an area where it was once thought that tropical storms could not form, as the Coriolis Force is not strong enough. However, warming global sea temperatures appear to be making this possible, as more heat is effectively more energy, and this is the fifth such near-equator storm of 2025. This means that communities in these areas are not as used to tropical storms as communities in areas where they are a long-standing problem, and infrastructure has not typically been built with large storms in mind, greatly increasing the damage and casualties caused when they appear.

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