Next Big Disaster? Power Failure During a Heat Wave

The convergence of two recent trends – more intense heat waves and more frequent power failures – could make the next large-scale disaster in the United States a power failure during a heat wave, a disaster that could cause thousands of deaths.

Extreme heat is already the deadliest form of extreme weather in the United States, causing more deaths on average than hurricanes and floods combined. Officials are investigating up to 800 heat-related deaths in this summer’s Pacific Northwest and California heat wave that shattered temperature records throughout the region.

The trend toward higher and more extreme temperatures is well documented.

  • The top nine hottest years on record all came over the past 10 years. 2020 was the hottest year on record
  • Heat waves occur three times more often than they did 60 years ago and are affecting 25 percent more land area
  • June saw the highest temperature ever recorded north of the Arctic Circle (100 degrees Fahrenheit) and tied the highest temperature ever recorded in Death Valley
  • Recent studies indicate that the frequency of extreme, record-breaking heat events will double in the coming decades

At the same time, power failures in the US are becoming more common.  Close to 5 million Texans lost power during a cold snap this past winter, and officials acknowledged the state power grid was minutes away from total collapse. Other recent warning signs:

  • The US experienced more than 100 major power outages between 2005 and 2015, more than double the previous decade
  • Last August, California experienced its worst blackout in two decades, leaving 800,000 residents without power
  • 100,000 residents in Michigan lost power in June following thunderstorms
  • California’s power grid operator has asked residents to reduce power consumption more than six times this summer alone to avoid outages

Many factors are contributing to the increase in power failures: lack of investment in aging transmission lines, choke points in the grid’s distribution system, the siting of solar and wind generation equipment far from urban areas, and increased demand. The steady increase in extreme weather events makes future power failures more likely, as spikes in use of air conditioners and lack of overnight cooling taxes regional power grids even further.

A widespread blackout during an extreme heat wave could lead to thousands of deaths, experts say.  High temperatures take a disproportionate toll on the elderly; however in extreme conditions, the entire population is at risk of heat stress. The human body cannot tolerate the combination of high humidity and temperatures above 95 degrees. Under those conditions, sweating no longer dissipates heat effectively, and heat stress quickly leads to heat exhaustion, organ failure, and death.

While every portion of the US is at risk, climate models suggest that going forward, the West Coast and Great Lakes regions may face the highest risk of that deadly combination of high humidity and extreme heat.

During the heat wave that hit the Pacific Northwest in June, about 17,000 electricity customers were without power in Washington State. In Idaho, Oregon, California and Nevada, nearly 20,000 more were in blackouts.

While not necessarily catastrophic, these numbers are a reminder that the United States’ infrastructure is not prepared for the inevitable increase in extreme meteorological events. (America’s electric grid beset by aging equipment, congestion and failures of transparency – The Washington Post).  The US power grid is often overloaded regionally, and the equipment is, on a local level, barely sufficient. Transmission lines are frequently congested and do not have the capacity to distribute enough power during peak load times.

A blackout during a heat wave could pose significant challenges to employers, office buildings, and residential towers.  During the day, urban workers could be unable to get home due to the loss of electrified mass transit, and buildings could be unable to provide cooling for those who remain. Water supplies could fail unless domestic pumps are connected to a generator. The risk of internal flooding increases when buildings cannot be cooled, as water in the sprinkler system expands and cracks sprinkler heads.

For more information on how to adapt your emergency response plan to anticipate this increasingly likely scenario, please contact AK Preparedness at