Humidity will soon build around Philadelphia and allow drenching thunderstorms to return at midweek.
Those with outdoor plans and projects should take advantage of the dry stretch of weather Monday through Tuesday. High pressure will be overhead during that time but will slowly depart.
A noticeable increase in humidity will occur on Tuesday, setting the stage for spotty afternoon thunderstorms to erupt toward Harrisburg. Thunderstorms should hold off for one more day around Philadelphia.
Wednesday is when the combination of the sticky air and a storm system moving in from the Midwest will bring numerous thunderstorms to the Philadelphia area.
The most active time of Wednesday is likely to be the afternoon when some of the thunderstorms will unleash blinding and flooding downpours.
Commuters may be faced with a slow ride home, while flight delays are possible. The storminess could also interfere with the Phillies game between the Miami Marlins at Citizens Bank Park Wednesday evening.
As long as the storm system creating Wednesday's storminess is not slower to depart, a dry Thursday should unfold before the thunderstorm chance quickly returns for Friday.
High temperatures will start this week in the lower 80s before rising to the upper 80s toward the weekend. Average highs for the end of June are in the middle 80s.
AccuWeather.com Senior Meteorologist Alex Sosnowski contributed to this story.
A new tropical threat may loom for the Caribbean and North America in the not-too-distant future, while eight more weeks remain in the Atlantic hurricane season.
The greatest danger of flooding across the central United States will unfold in western Texas, where downpours will be most persistent into Monday.
Fall air has finally arrived in the northeastern United States and may yield the first frost of the season in parts of the region this weekend.
Typhoon Megi will continue to strengthen before threatening lives and property across Taiwan and eastern China this week.
The first windstorm of the season could blast the northern United Kingdom around Tuesday as Karl arrives.
Hot, dry and windy weather into Monday will lead to an increased risk of wildfires across Southern California.
Southern CA (1970)
Record late September heat wave seared Southern CA for a week. L.A. hit 105 degrees; San Diego hit 97 degrees.
New Jersey (1975)
4-day rains of 7.50 to 11.00 inches. Flooding in northern part of the state.
Atlanta, GA (1989)
Torrential rain; 4.87 inches at Hartsfield Airport. This is the sixth greatest single rainfall on record. Atlanta Regional Hospital had 4.50 inches.