Philadelphia, PA Weather
Philadelphia hourly forecast: next 24 hours
Today's high of 87°F (30°C) is about 8°F (4°C) above the typical September high of 79°F (26°C).
Current conditions in detail
Philadelphia weather tomorrow (Friday, September 18)
Tomorrow in Philadelphia looks sunny, with a high of 84° and an overnight low of 70°. Rain is unlikely (7% chance). Winds top out near 9 mph, and the UV index reaches 7 (high).
Philadelphia 14-day forecast
About the weather in Philadelphia
Seasons are the whole story in Philadelphia. The gap between an average July and an average January is 25°C - hot, humid summers and generally mild winters - which in practice means 88°F (31°C) afternoons at one end of the calendar and 42°F (5°C) at the other.
Philadelphia weather: quick facts
- Hottest month: July - highs near 88°F (31°C)
- Coldest month: January - highs near 42°F (5°C)
- Decade extremes (2015-2024): 99°F (37°C) high · -7°F (-22°C) low
- Wettest month: July (14 rainy days) · Sunniest: July (11.6 h sun/day)
- Climate type: humid subtropical
- Annual swing: 25°C between the average warmest and coolest month · day to night: 9°C
- Snow: about 9 days a year
- Months averaging 30°C or hotter: 1
- Average humidity: 68%
Temperatures through the year
January is the coolest month, with highs of 42°F (5°C) and lows near 27°F (-3°C). At its warmest, in July, Philadelphia runs to 88°F (31°C) in the afternoon and back to 70°F (21°C) by dawn. Snow falls on roughly 9 days a year, mostly December through March.
Rain, sun and snow
Between the average July and the average January lie 25°C, a wider spread than roughly 81% of the cities we track. Overnight lows average at or below freezing for 2 months, January through February. The gridded 2015-2024 daily record for this location tops out at 99°F (37°C) and bottoms at -7°F (-22°C) - decade extremes, not all-time station records.
Season by season
Spring (March through May)
Through spring, Philadelphia runs cool rather than cold: 63°F (17°C) by day, 44°F (7°C) after dark, and rain falls on around 34 of the 90 days, plus about 2 snowy days.
Summer (June through August)
Summer in Philadelphia sits firmly in the heat, with daytime highs averaging 85°F (29°C) and nights around 67°F (20°C); rain falls on around 38 of the 90 days. Daylight is generous - around 11.2 hours of sun a day. With the moisture factored in, afternoons feel hotter than the reading suggests - the humidity and dew point converter shows why.
Fall (September through November)
Fall in Philadelphia is mild, with daytime highs averaging 68°F (20°C) and nights around 51°F (11°C); expect showers on roughly 27 days across the season.
Winter (December through February)
Winter in Philadelphia is brisk and cold, with daytime highs averaging 45°F (7°C) and nights around 29°F (-1°C); rain falls on around 31 of the 90 days, plus about 6 snowy days.
Average temperatures in Philadelphia by month
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 42° | 27° | 10 | 3.6 in | 6.0 h/day | 66% |
| February | 46° | 28° | 10 | 3.5 in | 6.9 h/day | 66% |
| March | 53° | 34° | 10 | 4.3 in | 7.9 h/day | 63% |
| April | 63° | 44° | 11 | 4.2 in | 8.9 h/day | 64% |
| May | 73° | 54° | 12 | 4.2 in | 9.7 h/day | 68% |
| June | 82° | 64° | 12 | 4.2 in | 11.2 h/day | 67% |
| July | 88° | 70° | 14 | 4.7 in | 11.6 h/day | 70% |
| August | 85° | 69° | 12 | 4.5 in | 10.7 h/day | 71% |
| September | 79° | 62° | 10 | 4.1 in | 9.0 h/day | 71% |
| October | 68° | 51° | 9 | 3.8 in | 7.9 h/day | 71% |
| November | 56° | 39° | 8 | 3.0 in | 7.4 h/day | 68% |
| December | 47° | 33° | 10 | 4.3 in | 5.8 h/day | 71% |