WMO: Recent water trends have serious future implications

WMO: Recent water trends have serious future implications

The WMO State of Global Water Resources report is a comprehensive science-based annual assessment of the hydrological cycle and extreme events in 2025 and over the past five years.

Geneva, Switzerland, 17 September 2026 (WMO) – Rivers across the globe in 2025 had one of the driest years in more than three decades, according to a new report from the World Meteorological Organization (WMO). It shows a continuation of the long-term decline in Earth’s freshwater storage and in glacier retreat - trends with serious implications for people and economies in the future.

The WMO State of Global Water Resources Report shows that the water cycle has become more erratic and unpredictable, swinging between too little or too much. The past seven years have seen the fewest rivers with “normal” flows since 1991.

Asia and Africa together accounted for at least half of all recorded water-related extreme events and more than 80% of reported associated deaths over the past five years, it says.

The report provides a comprehensive, science-based assessment of the entire water cycle loop, including river discharge, groundwater, evapotranspiration, land water storage, and snow and ice, as well as high-impact events. It covers the year 2025 and summarizes findings of the past five years since it was first published.

Some parts of this cycle are fast – such as precipitation, river flow, soil moisture – they respond to weather within days or weeks. Others, like groundwater, glaciers and seasonal snowpack, are slow, they accumulate or deplete over seasons to decades or longer. Traditionally these slow reserves have acted as the planet's savings account: a buffer that absorbs bad years so that a single drought or a single dry season does not translate directly into a water crisis,” said WMO Secretary-General Celeste Saulo.

“We are depleting that savings account. Global terrestrial water storage has shown a declining trend since 2014–2016 - a persistent, decade-long signal. For the fourth consecutive year, every major glaciated region on Earth lost ice mass. Groundwater tells a similar story: nearly two-thirds of monitored wells worldwide showed conditions outside the historical norm in 2025, and the balance shifted further toward deficit compared with 2024, not toward recovery,” said Celeste Saulo.

“At the same time, we are seeing more water-related disasters. The strengthening El Niño will increase the risk of drought in some areas, and flooding in others,” she said.

The report highlights some major areas of concern:

“Water respects no borders. A river basin's water balance depends on what happens in another country. A glacier's retreat in one country reshapes water availability for populations hundreds of kilometers downstream. This is precisely why we need shared data, shared standards, and shared early warning — the exact function WMO exists to perform,” said Celeste Saulo.

Dozens of experts from National Meteorological and Hydrological Services, data centres, researchers and partner institutions shared in situ observations, model outputs and space-based data and contributed to the report, which has expanded from three to 15 hydrological variables since the first edition in 2021. Country coverage has greatly expanded. However, Africa and Asia are still among the least represented regions in terms of hydrological observations in the report, even though they are most affected by extremes.

2025 was one of the warmest years on record. A weak La Niña emerged towards the end of the year after neutral conditions, and there was a predominantly negative Indian Ocean Dipole, which influenced precipitation.

Across the five reporting years (2021-2025), recurring below-normal river discharge was observed in major parts of the Amazon and La Plata basins, North America, Central and East Africa, Central Asia and the Middle East.

Annual river discharge in 2025 was above-normal to much-above-normal across South and South-East Asia and parts of northern South America. In Africa, there were above-normal flows in the Senegal, Niger, Lake Chad, Orange and Limpopo basins, but much-below-normal discharge in the Nile, Congo and Zambezi basins.

Below-normal to much-below-normal river discharge affected several major regions, including much of North America, the La Plata and São Francisco basins of South America, Eastern European basins, the Middle East and Central Asia.

Reservoir and lake levels followed similar geographical trends as for river basins. African lakes were largely much above normal, with Kariba a notable exception.

Terrestrial water storage shows a persistent negative trend since 2014-2016 with increasing area under below-normal conditions.

Between 2021-2025 below-normal terrestrial water storage repeatedly affected the south-western United States, Patagonia and the subtropical Andes, the Ganges–Indus headwaters, North Africa, the Middle East, Central Asia and eastern China, while persistent positive anomalies occurred in parts of sub-Saharan Africa, the Sahel and the Tibetan Plateau.

In 2025, it was below-normal in northern and southwestern North America, Patagonia, Eastern Europe, the Middle East, Central Asia, eastern Brazil, northern India, parts of Northern Europe, the Russian Federation, China and Northern Africa. La Plata in South America showed signs of partial recovery from the long-term drought.

Much-above-normal storage continued from 2024 into 2025 in Central and Southern Africa.

Persistent groundwater deficits were observed during 2022–2025 in parts of the Americas, Europe, the Middle East, India, southern Africa and Australia.

Persistent and widespread below-normal to much-below-normal groundwater levels were observed across Central and Eastern Europe, central United States, parts of Mexico, northern and central Chile, northeastern and central-western Brazil, northern South Africa, northwestern India and parts of southern Australia, pointing to a cumulative depletion with multi-year drying trend.

There were above-normal to much-above-normal conditions include parts of France, much of Northern Europe, the southeastern United States, large parts of South Africa, South-East Asia, and eastern Australia.

Snow conditions were below normal across Europe in 2025, whilst the Russian Federation and North America showed strong regional contrasts.

In the hydrological year 2025, glaciers lost 408 (±132) Gigatonnes of mass, equivalent to 1.1 (±0.4) mm of sea-level rise. It marked the fourth consecutive year in which every major glaciated region recorded a net loss.

Central Asia, South Asia West, Russian Arctic, Iceland, Western Canada and USA all recorded annual mass balances that ranked among the three most negative years on record for that region.

Some regions dominated by smaller glaciers, such as the Caucasus, Western Canada and the USA, and Central Europe may already have reached “peak water conditions,” the threshold where the glacier reaches its maximum runoff due to melting.

From 2021-2025, South America’s La Plata and Amazon basins, the Middle East and the Greater Horn of Africa experienced persistent multi-year drought conditions, while severe floods repeatedly affected West and Central Africa and South-East Asia.

Asia and Africa were the regions most affected by extreme hydrometeorological events in 2025, with several African countries experiencing major flooding for two (Nigeria) or three consecutive years (Democratic Republic of the Congo).

South and South-East Asia was hit by compound tropical cyclones and intense monsoon, leading to up to 3 600 deaths across affected countries - Sri Lanka, Pakistan, Viet Nam, Indonesia, Thailand, Malaysia, the Philippines.

Assessing the economic losses associated with water-related disasters remains challenging in many countries.

Jamaica reported that hurricane Melissa resulted in losses equivalent to 41% of GDP. Cyclone Ditwah cost Sri Lanka around 4% of GDP.

Severe drought gripped East Europe, the Mediterranean, and Middle East and also returned to the Greater Horn of Africa after one of the driest October–December seasons on record linked to La Niña and a negative Indian Ocean Dipole.

The WMO State of Global Water Resources 2025 report includes scientific contributions from dozens of WMO Members, partners and scientists.

Full details of the datasets, references and institutions involved are available in the report.

The WMO Secretariat wishes to thank everyone who dedicated their time and expertise to this report.

The World Meteorological Organization is the United Nations System’s authoritative voice on Weather, Climate and Water.