Fast Facts: The Cost of Multi-Hazard Disasters

Floods account for 35 to 40 percent of all weather-related disasters globally, and those waters are rising. Since 2000, the number of recorded flood disasters has risen by 134 percent, compared with the previous two decades. Flooding is also incredibly costly, with average annual losses nearing $390 billion, according to the United Nations Global Assessment Report 2025 on Disaster Risk Reduction.

The number of people exposed to floods globally has risen steadily since the 1970s, too—from 28.1 million to 35.1 million in 2020, a 24.9 percent increase. But natural disasters seldom occur alone, and multi-hazard events can increase losses beyond the sum of their parts.