Allentown, PA weather in August
August in Allentown: warm and often humid, with frequent rain. Highs 84°F, lows 63°F, about 10 days with rain. This is the peak of the warm season in Allentown.
- Normal high
- 84°F
- Normal low
- 63°F
- Wet days
- 10
- 4.6 in total
- Muggy days
- 12
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 86°F | 82°F |
| Normal low | 65°F | 60°F |
| Chance of a wet day | 34% | 31% |
| Sunrise / sunset | 5:59 am / 8:17 pm | 6:28 am / 7:36 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 am65°Fdew point 61°F
- 9 am73°Fdew point 63°F
- Noon80°Fdew point 62°F
- 3 pm81°Fdew point 62°F
- 6 pm78°Fdew point 62°F
- 9 pm72°Fdew point 63°F
NOAA hourly normals (local standard time) from Allentown Intl Airport (4 mi away); average wind 5 mph; clear or few clouds in 55% 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°F5 of 31
- Hot dayshigh 90°F or more5 of 31
- Muggy daysdaily mean dew point 65°F or more12 of 31
- Wet daysat least 0.01 in of rain or melted snow10 of 31
- Notable rainat least 0.10 in7 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 4.6 in; a dry August brings about 2.3 in and a wet one about 5.2 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 1 an inch or more.
How August varies from year to year
- Warmest August, 1991-20202016: average high 88°F
- Coolest August2000: average high 79°F
- Wettest August2011: 13.5 in
- Driest August1995: 0.8 in
- Highest reading99°F (August 14, 2002)
- Lowest reading45°F (August 21, 2000)
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 | 86°F | 84°F | 77°F |
| Normal low | 65°F | 63°F | 55°F |
| Wet days | 11 | 10 | 10 |
| Comfortable days | 3 | 5 | 14 |
| Daylight | 14.7 h | 13.7 h | 12.5 h |
Highs change by -2°F from July and -7°F into September.
Nearby alternatives in August
- Cooler: Worcester, MA223 mi · high 78°F · 10 wet days
How Allentown ranks in August
- Normal high225th warmest of 378 cities; 2nd of 4 in Pennsylvania
- Wet days272nd driest of 378
- Comfortable days141st most of 341
What to pack for Allentown in August
- A rain jacket or umbrella – rain on about 10 days
Heating and cooling
August has 3 heating degree days and 268 cooling degree days (base 65°F), 4% of the year's total heating and cooling demand.
Questions
How hot is Allentown in August?
The normal high is 84°F and the normal low is 63°F. From 1991 to 2020 the hottest August reading was 99°F (most recently on August 14, 2002).
Does it rain a lot in Allentown in August?
About 10 days in August have at least 0.01 in of precipitation, and the normal total is 4.6 in. The wettest August in 1991-2020 was in 2011 (13.5 in); the driest was in 1995 (0.8 in).
Is August a good time to visit Allentown?
August ranks 6th of 12 months on our comfort score for Allentown (54 out of 100). It has about 5 comfortable days and about 5 days at 90°F or hotter. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth, frost dates, humidity and wind by hour and cloud cover: Allentown Intl Airport (USW00014737), 3.6 mi NE of the city center, 390 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Lehigh Valley International Airport (725170-14737), 3.6 mi NE of the city center, 385 ft . Hourly observations, 1991-2020.