From the Himalayas to rural Texas, deadly floods this month have killed hundreds and exposed dangerous gaps in early warning systems, the UN’s weather agency warned, linking the devastation to rapid urbanization, land-use change and a warming climate that traps more moisture in the atmosphere.
The UN World Meteorological Organization (WMO) said on Monday that more intense downpours and glacier outburst floods are becoming increasingly frequent, with deadly consequences for communities caught off guard.
“Flash floods are not new, but their frequency and intensity are increasing in many regions due to rapid urbanization, land-use change and a changing climate,” said Stefan Uhlenbrook, WMO Director of Hydrology, Water and Cryosphere.
Each additional degree Celsius of warming enables the air to hold about 7 per cent more water vapour.
“This is increasing the risk of more extreme rainfall events. At the same time, glacier-related flood hazards are increasing due to enhanced ice melting in a warmer climate,” he added.
Thousands of lives lost every year
Floods and flash floods claim thousands of lives each year and cause billions of dollars in damage. In 2020, severe flooding across South Asia killed more than 6,500 people and caused $105 billion in economic losses.
Two years later, catastrophic floods in Pakistan left over 1,700 people dead, 33 million affected and losses exceeding $40 billion, reversing years of development gains.
This year, the onslaught has continued. In July alone, South Asia, East Asia and the United States have seen a string of deadly events, from monsoon rains to glacial lake bursts and sudden flash floods.
Asia reels from monsoon onslaught
In India and Pakistan, heavy monsoon rains have severed transport links, washed away homes and triggered landslides. Pakistan declared a state of emergency in its worst-hit areas, deploying military helicopters for rescue missions after forecasters warned of exceptional flood risk along the upper Jhelum River.
The Republic of Korea suffered record-breaking downpours between 16-20 July, with rainfall exceeding 115 mm per hour in some locations. At least 18 people were killed and more than 13,000 were evacuated.
In southern China, authorities issued flash flood and landslide alerts on 21 July, just a day after Typhoon Wipha battered Hong Kong, underscoring the compound risks of sequential storms.
Texas flash flood strikes overnight
Overnight 3 into 4 July, a sudden deluge turned Texas Hill Country into a disaster zone, killing more than 100 people and leaving dozens missing. In a few hours, 10-18 inches (25–46 cm) of rain swamped the Guadalupe River basin, sending the river surging 26 feet (8 metres) in just 45 minutes.
Many of the victims were young girls at a summer camp, caught unaware as floodwaters tore through sleeping quarters around 4 AM. Although the US National Weather Service issued warnings ahead of time, local sirens were lacking and the final alerts came when most were asleep.
Glacier outburst floods surge
Not all floods this month were caused by rain.
In Nepal’s Rasuwa district, a sudden outburst from a supraglacial lake – formed on a glacier’s surface – swept away hydropower plants, a major bridge and trade routes on 7 July. At least 11 people were killed and more than a dozen are reported missing.
Scientists at the International Centre for Integrated Mountain Development (ICIMOD), a WMO partner, say glacial-origin floods in the Hindu Kush-Himalaya region are occurring far more often than two decades ago, when one might strike every five to 10 years.
In May and June 2025 alone, three glacial outburst floods hit Nepal, Afghanistan and Pakistan, with two more in Nepal on 7 July. If warming continues, the risk of such floods could triple by the century’s end.
Closing the warning gap
The WMO is stepping up efforts to improve flood forecasting through its global initiative and real-time guidance platform, now used in over 70 countries.
The system integrates satellite data, radar and high-resolution weather models to flag threats hours in advance and is being expanded into a country-led, globally interoperable framework.
A 2022 World Bank study estimated that 1.81 billion people – nearly a quarter of the world’s population – are directly exposed to 1-in-100-year flood events, with 89 per cent living in low- and middle-income countries.
The UN’s Early Warnings for All initiative aims to ensure that everyone, everywhere, is protected by early warning systems by 2027.
https://news.un.org/en/story/2025/07/1165455
