The sun felt hotter than usual in Houston this week, as millions of sweltering residents emerged from the rapid thrashing of Hurricane Beryl to face a prolonged power outage — the largest ever seen by the city’s utility, according to the state’s lieutenant governor.

The outages from the storm affected as many as 2.7 million customers across the state, mostly in and around Houston. Despite a promise by the utility, CenterPoint Energy, to restore power to one million customers by the end of the day on Wednesday, large swaths of the nation’s fourth-biggest city remained without power.

The scale of the outages raised questions about whether enough had been done to prepare the city, just 50 miles from the Gulf Coast, for the kinds of storms that climate scientists predict will arrive with greater frequency.

“For a Category 1 hurricane to result in over a million customer outages in its immediate aftermath demonstrates that there is plenty of need for the resiliency hardening investments,” said Wei Due, an energy expert with PA Consulting and a former senior analyst and engineer for Con Edison.

Beryl was not a particularly strong storm when it made landfall early Monday. But the hurricane struck at the heart of Houston with a ferocity that toppled trees into power lines and that knocked over 10 transmission towers, officials said.

By late Tuesday, some 1.5 million of CenterPoint’s customers still had no power — and little sense of when it would return. Neighbors reported flickerings of light to each other on group chats, hoping for signs of progress. Many shared a map of open Whataburger locations, suggesting that the fast-food chain was a better way to find out about available electricity service, compared with the spotty information released by the utility.