May in Philadelphia features cool nights, comfortable afternoons, with 2-3 humid days near the end of the month.
Temperatures
Afternoon high temperatures early in May tend to be around 69-71 F (21-22 C) but will warm to 77-79 F (25-26 C) by the end of the month. \
A few of the warmer afternoons, especially later in the month, can reach up near 88 F (31C) and 1-2 days usually reach 90 F (32 C).
The record high temperature in Philadelphia during May is 97 F (36.1 C).
Late night and early morning low temperatures tend to be 50-52 F (10-11 C) early in the month, warming to 57-59 F (14-15 C) near the end of the month.
A few of the colder mornings, especially early in April, can dip down to around 41 F (5C) and the record low in Philadelphia is 31 F (-0.6 C).
Sky and Rain
During April, on average, you can expect about 6 sunny, 11 partly sunny, and 14 mostly cloudy days.
About 11 days this month will record some rainfall, however, only 2-3 days get significant rainfalls of 0.5 inches (12.7 mm) or more.
Daylight
The number of daylight hours continues to increase this month from about 13.9 hours on the 1st to 14.8 hours by the 31st.
Windspeed
Winds generally are light to gentle at 4-12 mph (6-19 kph) but can briefly be moderate at 13-18 mph (20-28 kph).
What to Wear in Philadelphia during May?
Spring weather prevails this month with a few days of summer-like temperatures likely near the end of the month.
Spring attire works best so pack both long and short-sleeve tops, jeans, a sweater, windbreaker or light jacket, sneakers, and some comfortable walking shoes.
For the few warmer afternoons bring along some lighter summer tops as well.
Things to Do in Philadelphia during May
With spring in full bloom, you might want to consider taking a pay-what-you-want Philadelphia walking tour, even if only to enjoy the weather.
During this time of year, you can usually expect there to be a lot of great concerts to attend. If you're a baseball fan, consider catching a Phillies game early in the season.
You can also look forward to a variety of theatrical shows, including musicals, stand-up comedy, and more.
For even more ideas, make sure to read our full post covering things to do in Philadelphia in May.
Fred Pickhardt
