America’s Second-Biggest Weather Killer Is Not What You Think

At Least 6 Killed In West Virginia Flash Floods

Deadly flooding in San Antonio and West Virginia in recent days is a reminder that this often overlooked danger is America’s second-biggest weather killer, even though other disasters like tornadoes and hurricanes make bigger headlines.

Big Picture

• Only Second To Heat Deaths: Over the past 10 years (2015-24), flooding has claimed an average of 113 lives each year in the U.S., according to NOAA. Heat is the only weather type to cause more deaths, with an average of 238 per year.

• All Flood Threats Can Be Serious: A huge, headline-making storm system is not required to produce deadly flooding. Summertime in particular is a time of year when smaller clusters of storms can produce extreme rainfall in a relatively small area, leading to rapidly rising floodwaters if the storms hover over the same location too long.
• Recent Flood Deaths Illustrate This: Thirteen lives were lost due to flooding in San Antonio on June 12, followed by six more killed in West Virginia on June 14-15. In both cases, the torrents were generated by localized heavy downpours in relatively small areas. San Antonio’s airport saw 3.98 inches of rain in a single hour during the height of its flash flooding, setting a record.

Deeper Dive

• Peak Time For Flash Floods Is Now: While flooding can happen any time of year, about 75% of flash flood reports between 2007 and 2017 happened from late April through mid-September, according to NOAA’s Weather Prediction Center (WPC).
• Why Flooding Is So Common: Warm, humid air is most abundant this time of year, which increases the rainfall potential for both individual thunderstorms and larger-scale weather systems in many parts of the country. Thunderstorms also have a greater chance to move more slowly in summer, sometimes concentrating extreme rainfall over one spot for too long. Check out this link for a deeper dive on why these warmer months are so prone to flooding.
• Rainfall Intensity Has Increased: A 2025 study by Climate Central found that 126 of 144 U.S. cities saw an increase in hourly rainfall intensity from 1970 to 2024. Rainfall hours became 15% wetter on average in those 126 cities, with the upper Midwest, Plains, Northern Rockies and Ohio Valley having the largest annual increases. That’s because climate change is increasing the intensity of extreme precipitation events since warmer air can hold more moisture.

More To Know

• Vehicles Are A Major Flood Death Contributor: Many flood deaths each year are avoidable. Driving into hazardous flood water has historically accounted for more than half of all flood-related drownings, according to NOAA, citing a CDC report. It may be tough to tell how deep the water is when you approach a flooded section of road, especially at night, so never try to proceed – instead, “Turn around. Don’t drown,” as the National Weather Service says.
• Take Warnings Seriously: Your local NWS office issues a flash flood warning when flash flooding is either already happening or expected to develop based on rainfall rates and radar trends. You should be aware of possible flooding in your area when one is issued and avoid travel if possible, especially at night. If a flash flood emergency is issued, that’s your signal the situation is dire, and you should avoid travel and head to higher ground if in a flood-prone location.

(MORE: Your Vehicle Can Be A Trap In A Flash Flood)

Chris Dolce has been a senior digital meteorologist with weather.com for 15 years after beginning his career with The Weather Channel in the early 2000s.