Heat Wave Leaves East Coast in Summer Daze

Unusually warm weather and record temperatures scorch the country.

By + More

The steamy, record-breaking first day of summer Wednesday is just the beginning for the United States as a scorching heat wave promises to bring triple digit temperatures to the midwest and northeast through Friday.

The National Weather Service has issued an Excessive Heat Warning in effect for the northeast Thursday including Maryland, Pennsylvania, New Jersey, and Delaware, with heat index values up to 105 degrees, and temperatures not expected to drop below 80 degrees overnight.

[Photo Gallery: Summer Heat Arrives in Full Force.]

NOAA also issued a Red Flag Warning for Las Vegas and surrounding areas Thursday, meaning that heat and air conditions are just perfect for critical fires. The service is warning residents to refrain from lighting any outdoor flames as fires could spread rapidly given the heat index.

The temperatures on the first day of summer broke records for dozens of cities and towns, with the heat at New York's LaGuardia Airport reaching 98 degrees — the hottest since 1953. In order to combat the dangerous heat wave, states are opening cooling centers for the homeless and those without air conditioning to escape and recover. New York City has 455 cooling centers open for the rest of the week.

Graduations on the East Coast created several emergency situations Wednesday as outdoor ceremonies took place despite extreme heat. In New Britain, Conn., 24 people were taken to a hospital after suffering heat-related symptoms while attending the New Britain High School graduation, according to the Associated Press.

[Read: What's Appropriate to Wear to Work in the Summer?]

But the highest tracked temperature on the first day of summer wasn't in the East but in Lamar, Colo., where temperatures reached a dangerous 108 degrees. Eleven other Colorado cities and towns also marked the highest record temperatures in the nation Wednesday.

But this isn't the beginning of warm temperatures for the year. Last month, the globally-averaged temperature marked the second warmest May since record keeping began in 1880.

Valerie Bonk is an assistant editor at U.S. News & World Report. You can contact her at vbonk@usnews.com or follow her on Twitter or Facebook.