Philadelphia, PA weather in August
In August, Philadelphia sees highs around 86°F and lows around 68°F: warm and often humid, with some rain. Expect about 9 wet days. It is one of the warmest months in Philadelphia.
- Normal high
- 86°F
- Normal low
- 68°F
- Wet days
- 9
- 4.3 in total
- Muggy days
- 16
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 87°F | 84°F |
| Normal low | 70°F | 66°F |
| Chance of a wet day | 31% | 28% |
| Sunrise / sunset | 5:59 am / 8:14 pm | 6:27 am / 7:34 pm |
| Daylight | 14.3 h | 13.1 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical August day
- 6 am70°Fdew point 64°F
- 9 am77°Fdew point 65°F
- Noon82°Fdew point 63°F
- 3 pm84°Fdew point 62°F
- 6 pm81°Fdew point 63°F
- 9 pm76°Fdew point 65°F
NOAA hourly normals (local standard time) from Philadelphia Intl Airport (7 mi away); average wind 8 mph; clear or few clouds in 59% of daytime hours, mostly cloudy or overcast in 31%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F3 of 31
- Hot dayshigh 90°F or more8 of 31
- Muggy daysdaily mean dew point 65°F or more16 of 31
- Wet daysat least 0.01 in of rain or melted snow9 of 31
- Notable rainat least 0.10 in6 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 4.3 in; a dry August brings about 2.5 in and a wet one about 5.0 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 2 an inch or more.
How August varies from year to year
- Warmest August, 1991-20202016: average high 90°F
- Coolest August2000: average high 81°F
- Wettest August2011: 19.3 in
- Driest August2001: 1.0 in
- Highest reading101°F (August 9, 2001)
- Lowest reading55°F (August 6, 1994)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 88°F | 86°F | 79°F |
| Normal low | 70°F | 68°F | 61°F |
| Wet days | 10 | 9 | 9 |
| Comfortable days | 1 | 3 | 12 |
| Daylight | 14.7 h | 13.7 h | 12.4 h |
Highs change by -2°F from July and -7°F into September.
Nearby alternatives in August
- Cooler: Montauk, NY184 mi · high 80°F · 9 wet days
How Philadelphia ranks in August
- Normal high196th warmest of 378 cities; 1st of 4 in Pennsylvania
- Wet days191st driest of 378
- Comfortable days167th most of 341
What to pack for Philadelphia in August
- Light, breathable clothing – highs near 86°F and about 16 muggy days
- A rain jacket or umbrella – rain on about 9 days
Heating and cooling
August has 1 heating degree days and 368 cooling degree days (base 65°F), 6% of the year's total heating and cooling demand.
Questions
How hot is Philadelphia in August?
The normal high is 86°F and the normal low is 68°F. From 1991 to 2020 the hottest August reading was 101°F (August 9, 2001).
Does it rain a lot in Philadelphia in August?
About 9 days in August have at least 0.01 in of precipitation, and the normal total is 4.3 in. The wettest August in 1991-2020 was in 2011 (19.3 in); the driest was in 2001 (1.0 in).
Is August a good time to visit Philadelphia?
August ranks 7th of 12 months on our comfort score for Philadelphia (50 out of 100). It has about 3 comfortable days and about 8 days at 90°F or hotter. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and humidity and wind by hour: Philadelphia Intl Airport (USW00013739), 6.8 mi SSW of the city center, 10 ft . NOAA normals and daily records, 1991-2020.
- Frost dates: Phila Franklin Inst (USC00366886), 0.6 mi NW of the city center, 60 ft . NOAA normals and daily records, 1991-2020.
- Cloud cover: Philadelphia Ne Airport (USW00094732), 12 mi NE of the city center, 100 ft (65 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Philadelphia International Airport (724080-13739), 6.4 mi SSW of the city center, 7 ft . Hourly observations, 1991-2020.