Lowcountry stuck on ‘broil’ through weekend Worst to come Friday, Saturday, with heat index of 108 forecast

Mark Hopkins and Rogue, an English mastiff, brave the heat for the July Fourth celebration at North Charleston’s Riverfront Park on Monday. It’s expected to get hotter and continue through the weekend.

So you think it’s been hot lately?

Well, it’s going to get hotter.

The heat wave that’s been baking the Lowcountry since Saturday is not expected to taper off until the middle of next week.

“What we’re seeing now is how it will be at least through Monday before we drop off a little bit,” said Michael Emlaw with the Charleston office of the National Weather Service. “We probably won’t get down to what’s typical for this time of year until at least mid-week.”

The normal afternoon high for this time of year is 91. The mercury at the Charleston International Airport, where the weather service keeps records, rose to 94 Saturday. It’s been hotter than that every day since.

Friday and Saturday are likely to be the worst yet, with temperatures in the high 90s and humidity that makes it feel much hotter. The weather service is predicting a heat index of 108.

It’s possible a temperature record could be broken Friday, although it’s not expected. The record was 100, set in 1986.

“I would say the odds of tying or breaking it are probably one in four, one in three, something like that,” Emlaw said. “Our thinking right now is we’ll come up a little bit short of that, but maybe not by much.”

The weather service doesn’t keep records for the heat index, the combination of temperature and humidity that determines how hot it feels. So it’s possible Friday could feel hotter than the day that set the record. But there have been times in Charleston when the heat index rose past 115 degrees, Emlaw said.

The record for Saturday’s date is 103, also set in 1986.

The temperature at the airport is generally a couple of degrees higher than downtown Charleston, which benefits from cooler air coming off the ocean. But that ocean air also means downtown Charleston air contains more moisture.

“So what you have happen is the slightly cooler temperatures are offset by the higher moisture content in the air, so the heat index isn’t all that different (between downtown and farther inland),” Emlaw said.

The nights have also been unusually hot. The normal low for this time of year is 72. Lately the mercury has been dropping barely below 80 at night.

“You’re not getting much of a cooldown, and all of a sudden you’re warming back up again,” Emlaw said.

Anybody who has to be outside much is cautioned to keep guzzling water. People are also urged to never leave pets of children in a parked car and are advised to check on the elderly to make sure they’re cool.

Reach Dave Munday at 843-937-5553.