Relative Humidity in Philadelphia, PA
The average annual humidity is 65%.
Local Climate Profile
Philadelphia experiences humid, sticky summers and moderately cold winters. Like much of the Northeast, controlling indoor humidity in summer is critical.
In Philadelphia, PA, the relative humidity fluctuates throughout the day. It is generally highest in the early morning, averaging 75% when the air is cool. As the sun heats the air throughout the day, the relative humidity naturally drops, reaching an average of 54% by the late afternoon.
Managing Indoor Comfort in Philadelphia, PA
Because outdoor weather directly impacts your indoor environment, residents of Philadelphia, PA must actively manage their home's humidity to stay within the ideal 30% to 60% range.
Since the local average is quite high, you should rely on your air conditioning and potentially a standalone dehumidifier to prevent mold growth and musty odors in your home.
Use the Calculator
If you have a hygrometer in your home, plug your current indoor temperature and humidity into the calculator above. It will instantly tell you the Dew Point and give you a comfort score!