Saturday "could end up being maybe the most oppressive day of the summer," Jim Hayes, a meteorologist at the weather service office in Mount Holly, warned on Friday.
The city has declared an excessive-heat warning, and the Philadelphia Corp. for Aging has activated its "Heatline" at 215-765-9040 - a phone service that offers tips on how to stay safe.
At PhiladelphiaPark, they are thinking of animal welfare too, canceling Saturday's schedule of live races (though simulcasts of races elsewhere are still on tap).
Ah, sweaty misery, how do we loathe thee? Let us count the ways:
Through Thursday, the temperature at Philadelphia International Airport has averaged 81.8 degrees for the month, 4.4 degrees above normal. The way forecasts are shaping up, the city is headed for its third-hottest July on record, a shade behind 82.4 in 1872 and 82.1 in 1994.
The last below-normal day in the city was July 2; there have been just six below-normal days in Philadelphia in the last two months.
In New Jersey, an average of official readings from around the state shows the second-hottest July on record so far, after 1955, said the state climatologist, David Robinson. Right now the month stands at 78.7 degrees - lower than Philadelphia because the calculation includes temperatures from the Shore and Sussex County in the northwest.
Blame the "Bermuda High," a high-pressure system that sits between Bermuda and North Carolina, pumping hot, humid air in our direction, Hayes said. The stubborn pattern has been lodged in place for several months, said Robinson, a member of the Rutgers University geography department.
"It's really been remarkably persistent since March," Robinson said.
It's gotten to the point where, in the weather service's online "discussion" of July's temperatures, an unidentified meteorologist spiked the otherwise sober prose with . . . an exclamation point.
"PHL . . . THROUGH THE 22ND . . . 15 DAYS 90 OR ABOVE!" the forecaster wrote on Friday.
Friday brought the total to 16 days this month when the high hit 90 degrees or above, and Saturday and Sunday are expected to raise it to 18.
In a typical year, there are 24 days when the temperatures hits 90 or above, according to the weather service. Philadelphia reached that total on July 11.
After this weekend, the year's total of 90-plus days should hit 35.
The rest of the world is feeling the heat, too. Globally, last month was the warmest June on record in combined land and ocean average surface temperature, according to the National Oceanic and Atmospheric Administration.
Locally, don't look for much relief any time soon, said Robinson, the New Jersey climatologist.
"When you get a hot summer," he said, "it's tough to get that heat out sometimes until you get to middle or late August."
Contact staff writer Tom Avril at 215-854-2430 or firstname.lastname@example.org.