A heavy winter storm sweeping across the United States has killed at least seven people and left more than 800,000 homes and businesses without electricity, triggering widespread disruptions to daily life.

The storm brought heavy snow, sleet and freezing rain, forcing authorities to close schools and roads and cancel thousands of flights. The National Weather Service (NWS) warned that “life-threatening” conditions stretched from Texas to New England.

Officials said two people died of hypothermia in Louisiana, while storm-related deaths were also reported in Texas, Tennessee and Kansas. In New York City, Mayor Zohran Mamdani said at least five people died on Saturday, although the exact causes were still being investigated. He noted that extreme cold remains a serious seasonal threat for residents.

More than 800,000 customers were without power by Sunday afternoon, according to PowerOutage.us. Meanwhile, FlightAware reported that over 11,000 flights were cancelled nationwide.

Meteorologists said the storm could last several days and affect about 180 million people  more than half of the US population. Freezing rain, which instantly turns into ice on contact with surfaces, was described as one of the most dangerous elements of the storm due to its ability to damage trees, down power lines and make roads extremely slippery.

National Weather Service meteorologist Allison Santorelli said,“The snow and ice will melt very slowly and won’t go away anytime soon, which will hinder recovery efforts.”

Read More: Winter storm leaves millions without power across US

New York Governor Kathy Hochul urged residents to stay indoors, calling it the coldest and most severe winter storm the state has experienced in years. Kentucky Governor Andy Beshear said ,the state was seeing more ice than initially forecast, increasing the risk of accidents.

Nearly half of US states have declared emergencies, while many schools cancelled classes through Monday. The US Senate also postponed a scheduled vote due to the severe weather.

Massive US winter storm cancels thousands of flights

The storm has also affected Canada, where heavy snowfall has led to hundreds of flight cancellations. Ontario is expected to receive between 15 and 30 centimetres of snow.

Weather experts said the storm was caused by a weakened polar vortex, allowing Arctic air to move southward. The extreme cold is forecast to persist into early February.

With inputs from BBC