Hurricanes, heatwaves, windstorms, wildfires and other extreme weather events in 2020 translated into significantly more time in the dark for customers of U.S. electric utilities. Utility customers experienced 1.33 billion outage hours in 2020, up 73% from roughly 770 million in 2019, according to PowerOutage.US, an aggregator of utility blackout data.

The outage tracker identified fewer outages in 2020 than in 2018, when it reported 1.48 billion outage hours, related largely to several major tropical storms that battered the East Coast and Gulf Coast states.

Among the top disasters responsible for the jump in outage hours in 2020 was Hurricane Isaias, which knocked out power for close to 14 million people as the tropical storm moved up the East Coast. In the Midwest, a derecho event (a sprawling windstorm associated with lines of powerful thunderstorms) in August also resulted in blackouts for some 4.1 million residents, while wildfires, high winds and heat waves left millions without power in the West.

Hurricane-prone Louisiana had the most U.S. outage hours in 2020, with 181 million outage hours of a total 19.39 billion hours tracked, a representative for the aggregator said in an email. California experienced 103.2 million hours of outages in 2020, down from 174.5 million in 2019, when Pacific Gas and Electric Co. rolled out a series of long-lasting precautionary power outages aimed at keeping its power lines from igniting fires during dry, windy weather.

Vendors of battery-backed solar arrays, traditional generators and other distributed energy resources in 2020 reported increased demand in California and other areas due to more frequent loss of grid power and concerns that climate change-linked extreme weather could exacerbate blackouts in coming years.

Despite the increase in blackout hours in 2020, outages totaled less than 1% of recorded customer-hours during the year, according to PowerOutage.US data.