It is day two of what could be the second heat wave of the year in Philadelphia and one coinciding with Fourth of July celebrations.

Besides the heat, another common refrain also appears in the forecast for the next three days: “a chance of showers and thunderstorms.”

First the heat wave.

The high temperature Tuesday at the Philadelphia International Airport was 91 degrees. The projected highs for the next two days are 91 and 90, respectively. Three 90-plus days in a row and you have a heat wave. The expected high for Friday is 89, so if there is a heat wave, its duration will be minimal.

Dew points, in the meantime, are in the low 70s and that means “comfort levels will take a hit," as the National Weather Service forecast discussion put it. In other words, it will be humid and feel hotter than the actual temperature.

The Independence Day forecast calls for at chance of showers and thunderstorms after 8 a.m., Otherwise it will be partly sunny during the day, turning mostly cloudy in time for the Fourth of July fireworks displays.

The weather service says the greatest chance of showers and thunderstorms will be west of the city.

At the Jersey Shore, there’s a chance of showers and thunderstorms between 8 a.m. and 2 p.m. on the Fourth. Otherwise, it will be mostly cloudy with a daytime high of 85, degrees, according to the forecast.

Showers and thunderstorms are likely during the day Saturday in Philadelphia and after 3 p.m. at the Shore.

The risk of rip currents Wednesday at the Shore is low.