Unseasonably warm temperatures in some US cities are breaking decades-old records this week as a heat wave sweeps through the central and northeastern states, according to the National Weather Service (NWS).

New York Gov. Kathy Hokul activated the Emergency Operations Center as the heat wave is expected to last through the weekend, affecting nearly 80 million people from Indiana to Maine.

24 hours after the mercury in Syracuse, New York, climbed to 34.4 degrees Celsius, the highest for the season since 1994, Gov. Hokul warned of the potentially deadly heat wave: “We’ve seen blizzards, we’ve seen floods, we’ve had hurricanes, we’ve had tornadoes… But this heat wave is very likely to cause more deaths.”

Beaches and public pools will be open from early morning to the public who will want to take advantage of tomorrow’s Juneteenth holiday to enjoy a few breaths of fresh air, the governor of New York said.

In Chicago, the maximum temperature reached 36.1 degrees Celsius at O’Hare International Airport, breaking the record of 35.5 degrees set in 1957.

Detroit and Philadelphia – as well as several areas in New Hampshire, Connecticut and Maine – are forecast to record record temperatures for the season in the next 24 hours, forecaster Mark Senard warned.

Michigan’s governor urged citizens to look out for their neighbors, especially the elderly who are most vulnerable to heat conditions. “Make sure they’re OK,” Gretchen Whitmer said.