Central Asia is experiencing declining river runoff, reduced terrestrial water storage, and some of the largest glacier mass losses on record, according to the World Meteorological Organization’s (WMO) new report, “State of Global Water Resources 2025.”

The report assesses global water resource changes between 2021 and 2025 and highlights growing pressure on water systems in several regions, including Central Asia.

According to the WMO, water inflows into reservoirs in Tajikistan, Uzbekistan, Kyrgyzstan, and Afghanistan were below or significantly below normal levels compared with the 1991–2020 average.

Similar trends were observed in parts of the Middle East, Eastern Europe, and North and South America.

River runoff remains below normal in Central Asia

Central Asia was among the regions where river runoff repeatedly remained below normal during 2021–2025.

The decline was particularly noticeable in the Aral Sea basin, which includes the region’s major river systems.

Globally, the period from 2021 to 2025 was among the driest on record for river runoff since observations began in 1991.

The WMO reported that river runoff was below normal across 36% of the world’s river basin area, normal across 36%, and above normal across 21%. By comparison, during 1991–2020, normal runoff levels were recorded across an average of 46% of river basin areas.

Water storage continues to decline

Terrestrial water storage in Central Asia remained below normal throughout the 2021–2025 period.

By 2025, water storage levels had remained below or significantly below normal for the second consecutive year, based on comparisons with the 2002–2020 period.

Terrestrial water storage includes water contained in rivers, lakes, reservoirs, soil, groundwater, snow, and ice.

The WMO assessment found that nearly half of the world’s monitored areas experienced reduced water storage, with 42% recording below or significantly below normal levels.

Regional reservoirs in Central Asia also showed declining storage levels, which the WMO linked to reduced water inflows.

Central Asian glaciers among those with largest losses

Central Asia’s glaciers recorded one of the three most negative mass balances worldwide during the hydrological year from October 2024 to September 2025.

This indicates that glaciers lost more ice than they accumulated during the period.

Significant glacier losses were also recorded in western South Asia, the Russian Arctic, Iceland, western Canada, and the United States.

Globally, glaciers lost an estimated 408±132 billion tons of ice during the year. It was the fourth consecutive period in which all major glacier regions worldwide experienced mass loss.

Between 2023 and 2025, global glacier losses reached about 1.4 trillion tons of water. Since 2000, mountain glaciers worldwide have lost 6.2% of their ice mass above sea level.

According to the technical annex to the WMO report, more than half of the total runoff in Central Asia’s river basins comes from snow and ice.

The organization warns that by the end of the 21st century, Central Asia could experience one of the world’s largest declines in summer glacier runoff, increasing pressure on water availability in the region.