Fox News Weather Center

First Heat Wave of Season Set to Sizzle East

Areas from the South to the Ohio Valley and mid-Atlantic states will sizzle for the latter part of this week as heat and humidity surge northward.

In some cases the hot and humid weather will last several days and in others it will be the start of long-term summerlike conditions.

Mini-Heat Wave to Visit Mid-Atlantic

According to AccuWeather Senior Meteorologist Dave Dombek, "This will likely be Philadelphia's first official heat wave of the summer season into the weekend."

A heat wave, in the Northern states, is three or more days in a row with temperatures reaching 90 F or higher. In the South, 90-degree temperatures are more routine in the summer.

Baltimore may also have three days of 90-degree temperatures.

In portions of the mid-Atlantic, temperatures will challenge record highs in the middle 90s Thursday and Friday.

Temperatures are forecast to reach 90 as far north as New York City and Cincinnati this week. Highs ranging from the upper 80s to the lower 90s will be common across the South.

AccuWeather RealFeel® Temperatures will climb several degrees higher due to sunshine, humidity, lack of wind and other factors. For several hours during the afternoon, RealFeel Temperatures will approach 100 F in parts of the mid-Atlantic and South.

People partaking in vigorous exercise or who must do manual labor should drink plenty of water and take breaks.

Fans and air conditioners will be abuzz during the pattern. High humidity levels will not only add to the discomfort during the day, but they will prevent temperatures from dropping off to cool levels at night in urban areas.

The weather pattern will offer a perfect opportunity to go to the beach or hang around the pool.

Farther north and west, temperatures will reach the upper 70s to lower 80s in the Great Lakes and New England, with a brief spike in temperatures expected on Friday.

Limited Cooling to Arrive This Weekend Across North

During the weekend, less humid and slightly cooler air will push across part of the Northeast.

According to AccuWeather Chief Meteorologist Elliot Abrams, unlike the unseasonable chill that occurred during the first week of June, this cool push will be more mild-mannered.

"Temperatures dipped into the 40s during early June in Boston, this time temperatures will only be trimmed back to the 70s in the city this weekend," Abrams said.

The boundary separating the slightly cooler and less humid air to the north from hot and steamy air in the south will cause showers and thunderstorms to ignite.

This zone of showers and thunderstorms is forecast to push southward during the weekend across the Northeast and Midwest.

The push of air from the north will take the edge off the heat and humidity in the Ohio Valley and mid-Atlantic for a day or two.

However, temperatures will likely remain above average indefinitely in these locations, which will translate to highs in the 80s to lower 90s and a continuation of summerlike conditions.

No significant change in heat and humidity is likely for the South this weekend into next week.