Philadelphia, Pennsylvania, features a humid subtropical climate with hot, humid summers and cold, sometimes snowy winters. The city experiences four distinct seasons, moderate to high rainfall year-round, and over 2,400 hours of sunshine annually, making it a dynamic destination for both urban exploration and outdoor activities.
The best times to travel section shows how the months compare for a visit, so you can find the time of year that fits what you want to do.
Background colours of the months:
The colour shows the typical temperature: yellow (hot), green (mild) and blue (cold). How strong the colour is shows the travel season: full colour means high season, soft colour means shoulder season and soft-striped means off season.
Weather symbols:
Each month has one symbol showing what the weather is typically like, such as hot and sunny, freezing or a rainy or snowy season. Use them to quickly spot months that match the weather you want, or to avoid the ones that don't.
Crowdedness:
The people icon shows how busy the place usually is. The more people, the more crowded it gets.
Additional notes:
The grey info boxes point out special things worth knowing, like recurring weather issues or seasonal events.
Philadelphia’s climate is shaped by its inland location and proximity to the Atlantic, resulting in significant seasonal contrasts. Summers (June–August) are hot, humid, and often wet, with average highs of 29–31°C and lows around 19°C. July is the hottest month, and heatwaves above 35°C are possible, though the city’s humidity can make it feel even warmer. Rainfall peaks in summer, with frequent thunderstorms and monthly precipitation averaging 100–110 mm. Sunshine is abundant, with up to 9 hours per day, and evenings can be muggy.
Winters (December–February) are cold, with average highs of 5–6°C and lows around -2°C. Snowfall is variable – some winters see only light snow, while others bring major storms. On average, Philadelphia receives 13–22 cm of snow per year, with January and February being the snowiest months. Winter days are short, with 4–5 hours of sunshine and about 9 hours of daylight. Spring (March–May) and autumn (September–November) are transitional, with mild to warm temperatures (13–23°C), blooming gardens or colourful foliage, and moderate rainfall. Rain falls year-round, totalling about 1,120 mm annually, and the city enjoys an average of 2,500 hours of sunshine per year. Winds are generally light to moderate (12–17 km/h), but can be brisk during storms or tropical remnants in late summer and autumn.
| Average climate data for Philadelphia, United States | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°C) | 3 | 5 | 10 | 16 | 22 | 27 | 30 | 29 | 25 | 18 | 12 | 7 | 30 |
| Average minimum temperature (°C) | -4 | -2 | 2 | 7 | 13 | 17 | 21 | 20 | 16 | 11 | 4 | 1 | -4 |
| Average precipitation (mm) | 21 | 21 | 27 | 30 | 33 | 37 | 39 | 42 | 22 | 23 | 26 | 30 | 351 |
| Average rainfall days (days) | 7 | 7 | 10 | 12 | 14 | 14 | 15 | 13 | 11 | 9 | 7 | 8 | 128 |
| Average snowfall (mm) | 22 | 25 | 14 | 2 | 3 | 0 | 0 | 0 | 0 | 0 | 2 | 5 | 73 |
| Average snowfall days (days) | 4 | 3 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 12 |
| Average relative humidity (%) | 74 | 76 | 72 | 70 | 76 | 75 | 71 | 71 | 76 | 77 | 73 | 76 | 74 |
| Average wind speed (km/h) | 13 | 14 | 14 | 14 | 11 | 10 | 9 | 9 | 10 | 12 | 12 | 12 | 12 |
| Average water temperature (°C) | 5 | 4 | 5 | 8 | 12 | 19 | 23 | 24 | 22 | 18 | 13 | 9 | 14 |
| Average daily daylight hours (h) | 9 | 10 | 12 | 13 | 14 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 12 |
| Average daily sunshine hours (h) | 5 | 4 | 6 | 8 | 8 | 10 | 10 | 10 | 8 | 5 | 5 | 5 | 7 |
| Average cloud coverage (%) | 45 | 46 | 46 | 42 | 47 | 37 | 31 | 31 | 37 | 40 | 38 | 45 | 41 |
| Average UV index | 2 | 2 | 3 | 4 | 6 | 6 | 6 | 6 | 5 | 4 | 2 | 2 | 4 |
The best time to visit Philadelphia is from late April to early June and September to mid-October, when temperatures are mild (18–25°C), humidity is lower, and the city’s gardens and parks are at their most vibrant. These periods offer comfortable weather for sightseeing, festivals, and outdoor activities, with fewer crowds than peak summer.
The least favourable time to visit is from late July to late August, when heat and humidity peak (often above 31°C), and thunderstorms are frequent. Winters (December–February) can also be challenging due to cold temperatures, variable snow, and shorter daylight hours, though the city is festive during the holidays.
Philadelphia’s annual average temperature is about 13°C. January is the coldest month (highs 5–6°C, lows -2°C), while July is the warmest (highs 30–31°C, lows 19°C).
Philadelphia receives about 1,120 mm of precipitation annually. Rain falls year-round, with July–September being wettest. Snowfall is variable, averaging 13–22 cm per year, but some winters see much more.
Philadelphia enjoys about 2,400–2,500 hours of sunshine per year. The sunniest months are June to August (up to 9 hours/day), while December and January are the least sunny (4–5 hours/day).
Late spring (April–June) and early autumn (September–October) are best for outdoor activities, with mild temperatures, lower humidity, and more sunshine. Summer is lively but can be hot and humid.
Philadelphia itself is not a winter sports destination, but nearby regions in Pennsylvania and New Jersey offer skiing and snowboarding from December to March, when snow cover is more reliable.
Swimming outdoors is most comfortable in July and August, when air temperatures reach 29–31°C and water temperatures in nearby lakes and the Atlantic reach 23–25°C.
Pack layers for spring and autumn, light clothing and sun protection for summer, and insulated, waterproof clothing for winter. An umbrella and rain jacket are useful year-round.
The warmest month, with the highest average maximum temperature, is July (30.2 °C). The month with the lowest average maximum temperature is January (3 °C). Overall, the average maximum temperature over the whole year is 17 °C.
The month with the highest average minimum temperature is July (20.8 °C). The coldest month, with the lowest average minimum temperature, is January (-3.7 °C). Overall, the average minimum temperature over the whole year is 8.8 °C.
The month with the highest average water temperature is August (24.4 °C). The month with the lowest average water temperature is February (4.3 °C). Overall, the average water temperature over the whole year is 13.6 °C.
The wettest month, with the highest amount of precipitation, is August (42.1 mm). The driest month, with the least amount of precipitation, is February (20.7 mm). Over the whole year there are 351.2 mm of rainfall on average.
The month with the most days of rain is July (14.8 days). The month with the fewest days of rain is February (7.1 days). Over the whole year there are 127.9 days of rain on average.
The month with the most snowfall is February (24.8 mm). The months with the least snowfall are June, July, August, September and October (0 mm). Over the whole year there are 72.6 mm of snowfall on average.
The month with the most days of snowfall is January (3.9 days). The month with the fewest days of snowfall is October (0 days). Over the whole year there are 11.6 days of snowfall on average.
The month with the highest average relative humidity is October (76.6 %). The month with the lowest average relative humidity is April (70.5 %). The overall average relative humidity over the whole year is 73.9 %.
The windiest month, with the highest average wind speed, is April (13.9 km/h). The calmest month, with the lowest average wind speed, is August (9.1 km/h). The overall average wind speed over the whole year is 11.6 km/h.
The month with the cloudiest skies, so the highest cloud coverage, is May (47.2 %). The month with the clearest skies, so the lowest cloud coverage, is August (30.9 %). Over the whole year there is an average cloud coverage of 40.5 %.
The month with the longest days, so the most daylight, is June (Average daylight: 15 h). The month with the shortest days, so the least daylight, is December (Average daylight: 9 h). Over the whole year there are 11.9 h of daylight per day on average.
The month with the most sunshine per day is July (Average sunshine: 10.2 h). The month with the least sunshine per day is February (Average sunshine: 4.2 h). Over the whole year there are 7.1 h of sunlight per day on average.
The months with the highest average UV index are May, June, July and August (UV index: 6). The months with the lowest average UV index are January, February, November and December (UV index: 2). Over the whole year the average UV index is 4.
