WASHINGTON: A brutal heatwave hit peak temperatures across the eastern United States on Friday, straining power grids, threatening World Cup matches and playing havoc with celebrations for America’s 250th independence anniversary.

With the heat index threatening to top 115F (46C), records could be broken in New York City, as extreme heat warnings blanketed the northeast and mid-Atlantic regions.

Combined with very humid air, the “feels like” temperature could reach 105F in Boston, 112F in Philadelphia, and 113F in Washington.

“Numerous daily temperature records are expected today and Indepen­dence Day, with some consecutive-day, monthly, and all-time records possible,” the Weather Service said. Hang Dang, a 76-year-old retiree, was not letting extreme temperatures deter her from attending celebrations in Washington for the 250th July Fourth anniversary.

“I came to the US in 1975 from Vietnam and... I was here for the bicentennial,” Dang told AFP, noting she drove 12 hours from Florida to attend festivities.