GENEVA, September 23 — The World Meteorological Organization published its State of Global Water Resources report on September 17, warning that rivers worldwide had one of their driest years in more than three decades in 2025, a finding with direct consequences for agriculture, hydropower and water-intensive industry from Central Asia to the Americas. The report, a science-based annual assessment of the hydrological cycle, states that the past seven years have seen the fewest rivers with “normal” flows since 1991.
The water cycle has become more erratic and unpredictable, swinging between too little and too much water, according to the findings.
A savings account running down
WMO Secretary-General Celeste Saulo said slow reserves such as groundwater, glaciers and seasonal snowpack have traditionally acted as the planet’s savings account, a buffer absorbing bad years. “We are depleting that savings account,” she said. Saulo said 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. Nearly two-thirds of monitored wells worldwide showed conditions outside the historical norm in 2025, with the balance shifting further toward deficit compared with 2024 rather than recovery.
Saulo also said the strengthening El Niño will increase the risk of drought in some areas and flooding in others.
Asia and Africa bear the brunt
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, the report states. Yet both regions remain among the least represented in terms of hydrological observations, even though they are most affected by extremes. Across the five reporting years from 2021 to 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, above-normal flows occurred 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 discharge affected 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, with African lakes largely much above normal except Kariba. The 2025 picture was shaped by one of the warmest years on record, with a weak La Niña emerging towards year-end after neutral conditions and a predominantly negative Indian Ocean Dipole influencing precipitation.
Data gaps and what comes next
The report covers river discharge, groundwater, evapotranspiration, land water storage, and snow and ice, as well as high-impact events. It has expanded from three to 15 hydrological variables since its first edition in 2021, with greatly expanded country coverage. Dozens of experts from National Meteorological and Hydrological Services, data centres, researchers and partner institutions contributed in situ observations, model outputs and space-based data.
Saulo said water respects no borders and that shared data, standards and early warning are the exact function WMO exists to perform. For Central Asian economies, the report’s finding of below-normal discharge across the region sits alongside the wider trend of declining terrestrial water storage.
Watch whether the expanded variable set and country coverage translate into better observation networks in the regions the report identifies as least monitored, and how the strengthening El Niño reshapes drought and flood risk through the coming season.
