Hot and humid conditions are expected to blanket Long Island starting Friday, lasting into the middle of next week — at least, meteorologists say.

Temperatures in the high 80s and low 90s are in the forecast, a smidgen cooler toward the East End, according to the National Weather Service.

Above-normal temperatures are forecast, bringing “typical summertime heat and humidity,” said Joe Pollina, weather service meteorologist based in Upton.

Thanks to that humidity, some days — Saturday and Tuesday particularly — could see “feels like” temperatures in the mid-90s, he said, as of Thursday afternoon’s forecast.

Friday evening and overnight, as well as Monday night, bring the potential for scattered showers and thunderstorms, the weather service said.

An air quality health advisory has been issued for Long Island, in effect Friday from 11 a.m. to 11 p.m., meaning an elevated level of ozone is expected, the state health department and state Department of Environmental Conservation said Thursday in a release.

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Those with respiratory issues, as well as young children and people who work or exercise vigorously outdoors, should limit strenuous outdoor activities from afternoon to early evening, when ozone levels are generally the highest, the release said.

“Hazy, hot, humid” describe Saturday and Sunday, said News 12 Long Island meteorologist Matt Hammer, and the heat is looking to persist into midweek.

Three consecutive days of 90 or above temperatures at Long Island MacArthur Airport would mean an official heat wave, he said.

The airport hasn’t seen such a string since 2013, from July 14 to 20, which was the longest stretch of 90s since records started being kept in 1984, according to the Northeast Regional Climate Center, based at Cornell University.

Whether the coming days make it official or not, overall conditions do indicate that Long Islanders who venture outdoors are going to find themselves sweltering.

What’s more, those who revel in this heat may celebrate at hearing that long-range forecasters say the end of the month, from July 26 to July 30, bring a 60 percent to 70 percent chance for above-normal conditions for the area that includes Long Island. That’s as opposed to right at or below normal, according to the Climate Prediction Center, which is under the umbrella of the National Oceanic and Atmospheric Administration.

The average high temperature for the month of July is 83.1 degrees, with the low 68.5, according to weather service data.

Ready for more? The center also said Thursday that August — as well as the period of August through October — are more likely than not to deliver above average temperatures.