More than 15 million people in the US north-east were bracing for “once-in-a-generation” Arctic blast on Friday and Saturday, as meteorologists warned frigid weather could bring record-breaking low temperatures.

An Arctic cold front is expected to bring wind chills of -50F (-45C) in parts of northern New England, and the National Weather Service (NWS) warned dangerous wind chills were likely in an area stretching from northern Pennsylvania to Maine.

The frigid weather will continue through Saturday evening, the NWS said. The icy blast in the north-east comes after a winter storm left hundreds of thousands of Texans without power on Thursday, after ice storms killed at least 10.

“The wind chills have the potential to be once-in-a-generation cold,” the NWS said, urging people to either stay indoors or take precautions against swiftly striking frostbite and hypothermia. The wind chill factor describes the combined effect of wind and cold temperatures on exposed skin.

In Boston, Mayor Michelle Wu declared a cold emergency for Friday through Sunday and has opened warming centers so people can get out of the cold.

In an advisory, the city suggested people wear several layers of loose-fitting lightweight, warm clothing.

“Wear mittens over gloves; layering works for your hands as well,” the advisory said. “Always wear a hat and cover your mouth with a scarf to protect your lungs.”

Record low temperatures could be set in the city, as well as in New York City, where wind gusts of 50mph were expected, and Providence, the NWS suggested in a tweet. It described the cold front as “a short-lived but impressive Arctic blast”.

In New Hampshire’s Mount Washington state park, atop the north-east’s highest peak, record-breaking wind chills of -110F (-79C) and wind speeds topping 100mph were expected.

“It’s definitely wicked cold, you can say that,” Frances Tarasiewicz, a weather observer for the park, told Reuters.

“Today it’s a seasonal 5F, but it’s coming at us quick,” he said of the cold blast headed for the Mount Washington observatory, where staff members live on the mountain in eight-day shifts.

Chris Sununu, the governor of New Hampshire, said the state could be facing “the coldest air that we’ve seen in years”. He advised people to stay indoors as much as possible, and to check on neighbors, relatives and the elderly.

The state warned that frostbite is possible within 15 minutes at the expected temperatures, and said hypothermia can occur within 10 minutes at -30F (-34C).

“This is an epic, generational Arctic outbreak,” said the National Weather Service in Caribou, Maine. It said the weather front will create a wind chill “rarely seen in northern and eastern Maine”.

“Temperatures this weekend will be extremely – and dangerously – cold across the state,” said Maine’s governor, Janet Mills.

“Please take extra precautions, be careful if you go outside, and be sure to check on your family, friends, and neighbors to make sure they are OK.”

Maine will open warming and charging centers across communities across the state, the governor’s office said.

In better news, the icy weather is expected to depart swiftly.

“T​his is about as short-lived a cold snap as you can get this time of year. The cold will already start to ease Saturday night,” the Weather Channel said.

As people in the north-east braced themselves for the cold, in the south temperatures began to rise on Friday after freezing weather left 430,000 people without power on Thursday.

The failures were most widespread in Austin, where impatience was rising among 150,000 customers nearly two days after the electricity first went out, which for many also means no heat. Power failures have affected about 30% of customers in the city of nearly a million at any given time since Wednesday.

Unlike the 2021 blackouts in Texas, when hundreds of people died after the state’s electricity grid was pushed to the brink of total failure, the outages in Austin this time were largely the result of frozen equipment and ice-burdened trees and limbs falling on power lines.

The freeze has been blamed for at least 10 traffic deaths on slick roads this week in Texas, Arkansas and Oklahoma.