A significant heat wave is predicted to impact central and eastern parts of the United States this week, with temperatures potentially exceeding previous records during the Fourth of July holiday weekend.
According to Marc Chenard, a meteorologist at the Weather Prediction Center, regions from the Midwest to the East Coast can expect temperatures ranging from the 90s to low 100s. In the East, particularly the Mid-Atlantic and the Northeast, the temperature could surpass 100 degrees.
Chenard highlighted that Washington, D.C., is expected to exceed 100 degrees for at least one or two days. Philadelphia and New York City are also forecasted to experience temperatures over 100 degrees, possibly breaking daily records in these cities on Thursday and Friday.
Philadelphia might match its June record high of 104 degrees. The heat wave will start affecting portions of the Plains on Sunday, with temperatures rising into the 90s. By Tuesday, the Great Lakes region, including Chicago, and the Gulf Coast will feel the heat. By Wednesday, the extreme heat will spread along much of the East Coast.
The high temperatures will pair with high humidity, worsening discomfort. The National Weather Service warns that heat index values, which account for both air temperature and humidity, could reach 110 degrees and locally up to 115 degrees.
Minimal relief is anticipated at night. Forecasts suggest that minimum temperatures will remain in the 70s, with some Eastern cities staying even warmer. Places like New York City, Philadelphia, and Washington, D.C., may experience nights with lows not dropping below 80 degrees. Chicago could also see nighttime temperatures near 80 on Tuesday or Wednesday morning.
These hot and humid conditions are expected to persist through most of the Fourth of July weekend. Chenard attributes the prolonged heat to a persistent area of high pressure, known as a heat dome. By the end of the holiday weekend, this heat dome is predicted to move westward toward the Plains, leading to cooler conditions in the East but increasing the chance for thunderstorms.