Excessive Heat in the United States

How dangerous are Excessive Heat events in the U.S.?

Per event, this hazard is far more dangerous than its frequency suggests. It ranks #13 by how often it is recorded among the 44 hazard types with at least 100 events, but #4 by fatalities per event, at 144.4 deaths per 1,000 recorded events. Recorded damage averages $500 per event. A reader scanning total counts would underestimate the risk of encountering one.

Human impact is a defining part of this hazard's NOAA record. Across 15,292 events, the database lists 2,208 fatalities and 2,950 injuries. PlainHazard places hazard types with at least 100 recorded fatalities in its very-high human-toll band. That is a descriptive grouping of this 2015-2025 catalog, not an official NOAA risk grade and not a statement about the severity of every individual event.

Geographic exposure is heavily concentrated in a handful of high-severity states. The three states absorbing the largest share of events are Arizona (1,812 events, 1,497 fatalities), Oklahoma (1,771 events, 2 fatalities), Texas (1,725 events, 49 fatalities), reflecting both physical geography (coastal exposure, plains corridors, terrain) and dense population sitting directly in harm's way. At the other end, states such as Vermont, American Samoa, Rhode Island report far fewer events, a genuinely rare event outside the leading states, not merely an underreported one.

This is a more frequency-heavy than loss-heavy record. The hazard ranks #13 by event count but #34 for combined property and crop damage, a gap of 21 places. Its listed losses represent <0.1% of the catalog total. The human-toll rank is #1, or 20.5% of recorded fatalities, so neither event count nor damage rank substitutes for the other.

The year-to-year record shows real volatility around a high baseline. The peak year on record was 2023, logging 5,024 events and $0 in property damage in a single calendar year. The most recent year in the dataset is 2025 with 1,439 events recorded. Across the full 11-year window, annual event counts reflect seasonal climate cycles (ENSO phases, active vs. quiet severe-weather years) and long-term shifts tied to a warming climate both help explain the swings.

NOAA entries are reports filed by local National Weather Service offices. Counts therefore reflect both observed weather and reporting practice; they do not measure unreported events, household exposure, or the probability of a future event at one address.