About 72 million people were under excessive-heat warnings Sunday, down from about 128 million on Saturday, according to the National Weather Service. Temperatures on Sunday reached the upper-90s to around 100 degrees from eastern Kansas into the Ohio Valley and from the mid-Atlantic into parts of New England. Atlantic City International Airport in New Jersey saw 100 degrees, breaking the previous July 21 record of 99 degrees.
High humidity made it feel even hotter. The heat index on Sunday ranged from 105 to 110 degrees from North Carolina to Boston, said Jim Hayes, a weather-service meteorologist, and reached 112 in places.
Saturday’s heat broke or tied records in a number of East Coast cities. Millinocket, Maine, reached 93 degrees, tying a record for the date. Manchester, N.H., set a record for the date of 97 degrees, breaking a mark set in 1949. And it hit 99 degrees at John F. Kennedy International Airport in New York, the highest on record for July 20.
At the same time, about 40 U.S. cities on Saturday tied or broke records for the highest minimum temperature on that date, as overnight temperatures remained in the high 70s or above 80 degrees across much of the Ohio Valley, mid-Atlantic and New England.
In Annapolis, Md., Saturday’s sultry low of 84 degrees broke a record for July 20. On Saturday, New York’s Central Park didn’t get below 82 degrees. That tied the record-high minimum for the date and was two degrees below the warmest low temperature observed for any date since record-keeping began back in 1869: 84 degrees.
In New York City, emergency medical workers and firefighters faced a surge in calls during the weekend’s extreme heat, city officials said. Calls for emergency medical services typically range between 4,000 and 4,500 on any day. On Friday, calls reached 4,606, and they soared to 5,143 on Saturday. As of noon Sunday, the city received 2,191 emergency calls.
Patients over 65 years old made up 70% of the 236 heat-related calls to 911 between Friday and noon on Sunday, a city official said.