170M Americans to Feel Sweltering Heat, Dangerous Humidity

The first major heat wave of the year is expected to bring extreme heat, high humidity and dangerous outdoor working conditions to millions across the central and eastern U.S. over the weekend into next week.

AccuWeather meteorologists say the heat wave will intensify just after the summer solstice, which officially arrives in the Northern Hemisphere on Friday.

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The heat is expected to cause energy demands to surge. In some areas, temperatures will challenge decades-old daily heat records, according to AccuWeather.

Meteorologists expect Philadelphia and Washington, D.C., to experience at least seven days with highs at or above 90 degrees, including at least two days with highs of 100 or higher next week. New York City is forecast to see multiple days with highs in the 90s. Temperatures are forecast to reach above 100 degrees in New Jersey and Long Island. Chicago residents can expect three to five days with high temperatures in the 90s, according to AccuWeather.

The forecast calls for high temperatures above 90 degrees for multiple days in Kansas City, Missouri and Oklahoma City. St. Louis and Nashville are likely to see at least eight straight days with highs of 90 to near 100. Meteorologists say highs may spike 5 to 15 degrees above the historical average in Atlanta and Charlotte during the heat wave.