Philadelphia weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Good
Best time to visit: April – June, August – October
What is the weather like in Philadelphia in August?
In August, Philadelphia is hot: daytime highs average 29 °C, and nights cool down to about 20 °C. The sea averages 24.5 °C – pleasant for swimming. The sun shines for around 7 hours a day. Rain is frequent, with about 11 rainy days and 93 mm in total. On about 11 days the thermometer climbs to 30 °C or more. The air is often humid and muggy. All in all, August is a good month for a holiday in Philadelphia.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 63 | 67 | 79 |
| Day | 30° | 29° | 25° |
| Night | 21° | 20° | 16° |
| Sea | 24° | 25° | 23° |
| Sun | 8 h | 7 h | 6 h |
| Rain days | 11 | 11 | 9 |
More details for August
- Daylight
- 13 h 48 min06:12 – 19:59
- UV index
- 8 · very highclear sky, noon (estimate)All months
- Muggy days
- 16 daysdew point 18 °C or moreAll months
- Wind
- 14 km/haverage daily peakAll months
- Cloud cover
- 54 %on averageAll months
- Hot days
- 11 days30 °C or moreAll months
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC−4America/New_York
How the score comes together
- Temperatureweight 50 %77 %
- Sunshineweight 20 %63 %
- Few rainy daysweight 30 %52 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in August
- Swimwear
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- Water bottle – drink plenty
- Insect repellent
- Rain jacket or umbrella
Philadelphia in August: quick answers
Is Philadelphia hot in August?
Yes. In August, Philadelphia is hot: daytime highs average 29 °C and nights stay around 20 °C. On about 11 days the thermometer climbs to 30 °C or more.
Can you swim in Philadelphia in August?
Yes. In August the sea averages 24.5 °C – pleasant for swimming.
Does it rain much in Philadelphia in August?
Rain is frequent, with about 11 rainy days and 93 mm in total.
Philadelphia month by month
The whole year in PhiladelphiaAll destinations: USAWhere to go in AugustSea temperature in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences