Philadelphia Weather in May
May is one of the perfect months to visit Philadelphia, with daytime temperatures of 24°C (75°F) and lows of 14°C (57°F) at night. Do note that quite a bit of rainfall is typical, averaging around 92 mm (3.6 in).
Rainfall in Philadelphia in May
The climate data from previous years indicates about 12 days of rain, averaging 92 mm (3.6 in) for the month. The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.
Temperature in Philadelphia in May
The perfect temperature in Philadelphia in May makes it a solid month to visit, with 24°C (75°F) during the day and 14°C (57°F) at night. The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. Nights drop to around 14°C (57°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable.
Sunshine in Philadelphia in May
Expect sunny days throughout the month, with an estimated 247 hours of sunshine. This makes it a pleasant time to visit Philadelphia.
Average water temperature in May
At 12°C (54°F), the water is too cold for most people to swim comfortably. A wetsuit is pretty much essential if you plan to go in.If you're a fan of comfortable temperatures and drier conditions, May is a great time to visit.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Philadelphia's climate page.
Philadelphia Temperature in May
Min Temperature
14°C (57°F)
Max Temperature
24°C (75°F)
Water Temperature
12°C (54°F)
Chance of Rain
40%
Precipitation
92 mm (3.6 in)
Rainy days
12 days
Humidity
66%
Sunshine
247 hours
Percentage Sunshine
55%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Philadelphia typically rise from around 21°C (70°F) at the start of May to approximately 26°C (79°F) by the end. Nights are cool, with lows typically ranging from 10°C (50°F) to 16°C (61°F).
Average temperatures in May
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in May
Historical weather for Philadelphia in May
Browse day-by-day weather records for Philadelphia spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Philadelphia historical weather extremes in May
Based on 50 years of weather observations in Philadelphia between 1976 and 2026, these are the recorded extremes.
- On May 19, 2026, temperatures climbed to 36°C (97°F), marking the warmest May day on record.
- Nighttime temperatures dropped to 1°C (34°F) on May 1, 1978, marking the coldest May night on record.
Best Places in the United States of America in May
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in May →
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What to Wear in Philadelphia in May
For Philadelphia in May, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. High rain levels are expected, so pack waterproof gear and an umbrella or poncho. The water temperature sits at about 12°C (54°F), which is too chilly for most people to enjoy swimming. Leave the swimsuit at home unless you love cold water. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.What To Do in Philadelphia in May
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Philadelphia's climate page.
Temperature Rainfall Sunshine Humidity Water Temp
See the full Philadelphia climate overview or explore weather in the United States of America.
