Philadelphia weather in August: Philadelphia, Pennsylvania: normal highs, lows, rain and records for August
Philadelphia in August has a normal high of 86°F and a normal low of 68°F, a daily mean of 77°F, falling from 87°F on the 1st to 84°F by the 31st. Measurable precipitation falls on 9 days in a normal August, 4.29 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 30°C and low of 20°C, 109 mm of precipitation in August.
- NOAA stationPhiladelphia International Airport
- Station IDUSW00013739
- Location39.87°N 75.23°W
- Elevation10 ft (3 m)
- From the center11 miles
- Population1,573,916
- Jan 41° 26°
- Feb 44° 28°
- Mar 53° 34°
- Apr 65° 44°
- May 74° 54°
- Jun 83° 64°
- Jul 88° 70°
- Aug 86° 68°
- Sep 79° 61°
- Oct 67° 49°
- Nov 56° 39°
- Dec 46° 31°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Philadelphia in August?
The normal high is 86°F and the normal low 68°F, for a daily mean of 76.8°F. August is 1.9°F cooler than July and 6.9°F warmer than September. August is the 2nd warmest month of the year in Philadelphia and the 3rd wettest. Across the month the normal high falls 3°F, from 87°F on August 1 to 84°F on August 31. From one year to the next August's mean temperature typically moves about 2.2°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 75°F and 79°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 32%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 87°F | 70°F | 32% | 21% |
| August 8 | 87°F | 69°F | 31% | 20% |
| August 15 | 86°F | 68°F | 30% | 19% |
| August 22 | 85°F | 67°F | 28% | 18% |
| August 31 | 84°F | 66°F | 28% | 17% |
Every day of August: normal high, low and chance of precipitation (warmest afternoon August 1, coldest night August 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| August 1 | 87°F | 70°F | 32% | 21% | 14 h 20 min |
| August 2 | 87°F | 70°F | 32% | 21% | 14 h 20 min |
| August 3 | 87°F | 69°F | 32% | 20% | 14 h 10 min |
| August 4 | 87°F | 69°F | 31% | 20% | 14 h 10 min |
| August 5 | 87°F | 69°F | 31% | 20% | 14 h 10 min |
| August 6 | 87°F | 69°F | 31% | 20% | 14 h 10 min |
| August 7 | 87°F | 69°F | 31% | 20% | 14 h 10 min |
| August 8 | 87°F | 69°F | 31% | 20% | 14 h |
| August 9 | 87°F | 69°F | 31% | 20% | 14 h |
| August 10 | 87°F | 69°F | 31% | 20% | 14 h |
| August 11 | 87°F | 69°F | 31% | 20% | 14 h |
| August 12 | 86°F | 69°F | 30% | 20% | 13 h 50 min |
| August 13 | 86°F | 69°F | 30% | 20% | 13 h 50 min |
| August 14 | 86°F | 68°F | 30% | 20% | 13 h 50 min |
| August 15 | 86°F | 68°F | 30% | 19% | 13 h 50 min |
| August 16 | 86°F | 68°F | 30% | 19% | 13 h 50 min |
| August 17 | 86°F | 68°F | 30% | 19% | 13 h 40 min |
| August 18 | 86°F | 68°F | 29% | 19% | 13 h 40 min |
| August 19 | 86°F | 68°F | 29% | 19% | 13 h 40 min |
| August 20 | 86°F | 68°F | 29% | 19% | 13 h 40 min |
| August 21 | 85°F | 67°F | 29% | 18% | 13 h 30 min |
| August 22 | 85°F | 67°F | 28% | 18% | 13 h 30 min |
| August 23 | 85°F | 67°F | 28% | 18% | 13 h 30 min |
| August 24 | 85°F | 67°F | 28% | 18% | 13 h 30 min |
| August 25 | 85°F | 67°F | 28% | 18% | 13 h 20 min |
| August 26 | 85°F | 67°F | 28% | 18% | 13 h 20 min |
| August 27 | 85°F | 66°F | 28% | 18% | 13 h 20 min |
| August 28 | 84°F | 66°F | 28% | 17% | 13 h 20 min |
| August 29 | 84°F | 66°F | 28% | 17% | 13 h 10 min |
| August 30 | 84°F | 66°F | 28% | 17% | 13 h 10 min |
| August 31 | 84°F | 66°F | 28% | 17% | 13 h 10 min |
- Normal high
- 86°FAugust average
- Normal low
- 68°FAugust average
- Precipitation
- 4.29 inmonth total
- Days with precipitation
- 90.01 inch or more
- Days at 90°F or more
- 8
- Daylight
- 14 h 20 min to 13 h 10 minAugust 1 to August 31
- Days at 70°F or more
- 31
- Days at 80°F or more
- 27
- Sunshine
- 80%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00013739; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Philadelphia in August?
On a given August day the chance of 0.01 inch or more is 30% on average, highest around August 1 (32%). In all, 4.29 in falls on 9 days of a normal August, 2 of them with an inch or more.
In a normal August in Philadelphia, 8 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00013739.
How humid and windy is Philadelphia in August?
At 3 p.m. the normal temperature is 82°F with 48% relative humidity and a dew point of 61°F; at 6 a.m. it is 68°F with 81% humidity. The wind averages 8.0 mph, most often from the west-southwest in the afternoon.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 68°F | 62°F | 81% | 6.4 mph | 34% |
| 9 a.m. | 75°F | 63°F | 66% | 8.7 mph | 40% |
| noon | 80°F | 61°F | 52% | 9.1 mph | 29% |
| 3 p.m. | 82°F | 61°F | 48% | 10.0 mph | 23% |
| 6 p.m. | 79°F | 61°F | 54% | 9.6 mph | 30% |
| 9 p.m. | 74°F | 63°F | 69% | 7.4 mph | 47% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00013739. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for August in Philadelphia?
The warmest August temperature on Philadelphia's official record (since 1873) is 106°F, on August 7, 1918; the coldest is 44°F, on August 29, 1986. The wettest August brought 19.31 in (2011).
The August mean against the 1991-2020 normal of 76.8°F: 2021 79.2°F (+2.4), 2022 81.3°F (+4.5), 2023 76.8°F (at normal), 2024 77.0°F (+0.2), 2025 74.8°F (−2.0), 2026 79.2°F (+2.4). 4 of 6 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 79.2°F | +2.4°F | 6.18 in |
| 2022 | 81.3°F | +4.5°F | 2.70 in |
| 2023 | 76.8°F | at normal | 3.25 in |
| 2024 | 77.0°F | +0.2°F | 5.07 in |
| 2025 | 74.8°F | −2.0°F | 1.73 in |
| 2026 | 79.2°F | +2.4°F | 7.44 in |
Source: records: ACIS, NWS threaded record PHLthr; recent months: ACIS, station USW00013739. Records and recent months use complete months only.
How does August in Philadelphia compare across Pennsylvania?
Across the 108 places PlainClimate covers in Pennsylvania, August normal highs run from 75°F in Laporte to 87°F in Marcus Hook; Philadelphia's is 86°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Philadelphia in July88°F by day, 70°F at night
- Philadelphia in September79°F by day, 61°F at night
- Philadelphia through the yearEvery month, frost dates, records and recent years
- Pennsylvania in AugustThe statewide normal and the warmest and coolest places
- Marcus Hook: Pennsylvania's warmest Augustnormal high 87°F