The Big Apple will bake this weekend as a heat wave sends the mercury up to temps in the mid-90s, with heat indexes above 100, forecasters predict.

Temperatures on Tuesday and Wednesday are expected to top out around a sticky 90 degrees — and then cool down slightly to 85 degrees as a thunderstorm rolls in, dumping the remnants of Tropical Storm Barry on the region, AccuWeather senior meteorologist Tom Kines said.

But then Mother Nature will crank up the heat again Friday, with temperatures expected to hit as high as 93 degrees — but it will feel more like 103, according to early predictions.

Saturday will be a scorcher, with temps soaring up to 95 degrees, but the heat index will make it feel like 105. Sunday will again be around 93 degrees, with a real feel of 104, AccuWeather predicts.

Based on numbers alone, Saturday looks to be the worst — but all three days will be extremely uncomfortable, according to Kines.

“It wouldn’t surprise me if Sunday was just as nasty, and Friday’s no picnic either,” the forecaster said.

“It’s going to be pretty stifling,” he added. “And there’s probably going to be one or two nights at least in the city where temps don’t get down below 80.”

But the hot spell is more or less par for the course this time of year, he said.

“I don’t think there’s anything unusual about it,” Kines said. “We get these spells in the summer. It happens, but it is going to be oppressive out there. It is a big deal.”

The last heat wave roasted the Big Apple from June 30 to July 3 last year, according to Kines.

The extreme temperatures could mean that another blackout is on the way — after outages struck much of Manhattan for five hours Saturday evening, leaving some 73,000 residents without power at its height.

“We expect that there could be service outages — those things happen during heat waves,” Con Edison spokesman Mike Clendenin said Monday.

Later in the day, Con Ed further fueled fears of a potential power outage when it completely backtracked and blamed a fault in a 13,000-volt power cable that caught fire for triggering Saturday’s blackout.

Kines urged New Yorkers to drink plenty of water, wear light clothing and stay in air conditioning if possible over the weekend.