Deadly Global Floods Underscore Urgent Need for Early Warning Systems

In a stark reminder of escalating climate risks, July and early August 2025 brought deadly floods to Asia and the United States, killing hundreds and causing billions in economic losses. The scale and frequency of these flash floods have intensified concerns about the global community’s readiness to protect vulnerable populations through timely and effective early warning systems.

Countries including China, India, Nepal, Pakistan, and South Korea were battered by extreme rainfall, flash floods, and landslides, while in the United States, Texas and New Mexico suffered catastrophic deluges, killing over 100 people. According to experts from the World Meteorological Organization (WMO), the surge in these disasters is closely tied to climate change, rapid urbanization, deforestation, and poorly managed land use.

Flash Floods: Rising and Raging Faster Than Ever

“Flash floods are not new,” said Stefan Uhlenbrook, Director of Hydrology, Water and Cryosphere at WMO. “But their frequency and intensity are increasing in many regions due to rising global temperatures, urban development, and shifting land-use patterns.”

A warmer atmosphere can hold about 7% more water vapor per degree Celsius, leading to more intense rainfall events. Additionally, glacier melt in mountainous regions is contributing to new kinds of flood risks, especially in the Hindu Kush Himalaya (HKH).

According to WMO’s Hwirin Kim, “Floods and flash floods are a key threat to lives and infrastructure and are therefore one of the priorities of the Early Warnings for All initiative.”

Asia: Multiple Countries Slammed by Monsoon Floods

India and Nepal: Himalayan Horror

On 5 August, flash floods devastated Dharali village in Uttarkashi, India. Despite early warnings issued by the India Meteorological Department, over 100 people were reported missing, many swept away by floodwaters and mudslides following heavy upstream rain in the Kheer Ganga river catchment.

India is a core participant in the South Asia Flash Flood Guidance System, which also supports Bhutan, Bangladesh, Nepal, and Sri Lanka—covering over 2 billion people. However, the tragic outcome in Dharali underscores the need for improved warning communication and local action systems.

Nepal also suffered a deadly blow when a glacial lake outburst flood (GLOF) hit Rasuwa district on 7 July, killing seven and leaving 19 missing. The flood originated from a supraglacial lake in China's Tibet region, which had formed rapidly over just a few months due to record warming.

China: Fatal Floods in the Capital

Beijing saw its heaviest rainfall in decades between 4–5 August, forcing the evacuation of tens of thousands. At least 40 people died during late July flooding, prompting authorities to activate emergency flood response protocols across the northwest.

Pakistan: A State of Emergency

After devastating floods in June and July, Pakistan declared a state of emergency in its worst-hit provinces. The Jhelum River reached dangerous levels, with flood alerts issued by the Pakistan Meteorological Department, and rescue operations carried out with army helicopters.

Republic of Korea: Record Rainfall and Landslides

Between 16–20 July, South Korea's southern regions were inundated with rainfall exceeding 115 mm/hour. Widespread landslides, power outages, and transport disruption followed, leading to at least 18 deaths and the evacuation of 13,000 people. Notably, Sancheong, previously impacted by wildfires, was overwhelmed as the scorched terrain failed to absorb the downpour.

United States: Catastrophe in Texas Hill Country

On 4 July, a deadly flash flood ripped through Kerr County, Texas, killing more than 100 people, many of them children at summer camps. A mesoscale convective complex formed from tropical moisture and local storms, dumping 10–18 inches (25–46 cm) of rain in hours.

Although the National Weather Service issued multiple warnings—including a flash flood emergency—the disaster struck at 4 a.m., when most were asleep. The absence of local sirens at camps compounded the tragedy. The Guadalupe River rose 26 feet (8 meters) in just 45 minutes, overwhelming even experienced emergency responders.

The region’s rocky terrain and low soil absorption exacerbated the crisis, highlighting the importance of localized, real-time warning mechanisms.

Glacier Melt: A New Flood Frontier

The International Centre for Integrated Mountain Development (ICIMOD) reports a troubling surge in glacier-related floods. In the 2000s, the HKH region would see one every 5–10 years. But May and June 2025 alone witnessed three separate GLOFs in Nepal, Afghanistan, and Pakistan.

On 7 July, two GLOFs occurred in Nepal—Rasuwa and Upper Mustang—highlighting the accelerating risk. Experts forecast a three-fold increase in GLOF risk across HKH by the end of the century.

WMO’s Global Cryosphere Watch Programme and ICIMOD are focusing this International Year of Glaciers’ Preservation on raising awareness and improving monitoring in glaciated regions.

Global Trends and Economic Costs

Flash floods now account for 85% of all flooding cases and have the highest mortality rates, causing over $50 billion in losses annually. Vulnerability is especially high in low- and middle-income countries, which house 89% of the 1.81 billion people exposed to 1-in-100-year floods, according to the World Bank.

Some of the deadliest floods in recent years include:

• 2020 South Asia Floods: 6,511 fatalities, US$105 billion in damages

• 2022 Pakistan Floods: 1,700+ deaths, US$40 billion in losses

• 2024 Europe, MENA Floods: US$36 billion in economic losses

WMO: Tools and Training for Forecasting and Preparedness

The WMO operates the Flash Flood Guidance System (FFGS) and Flood Forecasting Initiative (FFI), both used in over 70 countries. These systems integrate satellite data, radar, and high-resolution weather models to support short-term flood forecasting.

WMO is currently transitioning FFGS into a Member-led, globally governed system, ensuring long-term sustainability and interoperability. Its goal is to embed flood warnings into national Multi-Hazard Early Warning Systems (MHEWS), which help communities prepare for multiple simultaneous risks.

WMO also certifies forecasters through its Flash Flood Forecasting Competency Framework, providing nations with a trained workforce capable of interpreting warnings and activating emergency responses.

A Global Call to Action

The floods of July–August 2025 are a wake-up call. They illustrate that while technological tools and weather models have improved, the last-mile delivery of early warnings—especially to remote or sleeping populations—remains a life-and-death challenge.

As the climate warms, global flood risks will continue to rise. The call from WMO is clear: investment in forecasting, public education, warning systems, and infrastructure must accelerate, or the human and economic toll will keep rising.