Allentown weather in August

In August, Allentown sees average daytime highs of 83°F and overnight lows near 65°F, with 3.7 in of rain across 10.1 wet days and about 13.6 hours of daylight. It is the 2nd-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 85°F in the first days to 82°F by the end. The sky is clear or mostly clear about 29% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 h 12 min at the start of August to 13 hours by month's end. Set against the rest of the year, August is Allentown's 3rd-clearest and 12th-windiest month. For the whole year in context, see Allentown's year-round climate.

Daytime high
83°
2nd warmest
Overnight low
65°
11th coldest
Rainfall
3.7 in
10.1 wet days
Daylight
13 h 36 min
5:17 AM – 6:55 PM
Cloud cover
59%
3rd clearest
Wind
5 mph
12th windiest
Solar energy
5.22 kWh/m²
Travel score
5.8
out of 10

Allentown is city in and seat of Lehigh County, Pennsylvania, United States.

Density
2,575/km²
people per km²
Founded
1762

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 85°F in the first days to 82°F by the end.

A typical August day in Allentown reaches about 83°F in the afternoon and slips back to 65°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 76°F and 91°F. Set against its neighbours, August runs about 2°F cooler than July and about 7°F warmer than September.

50°60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18567
28567
38567
48567
58567
68566
78466
88466
98466
108466
118466
128466
138466
148365
158365
168365
178365
188365
198365
208365
218364
228364
238264
248264
258264
268264
278264
288263
298263
308263
318163

How August really feels in Allentown

Once humidity and wind are folded in, August averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Allentown weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan38° / 24°3.49.54.89.40.0
Feb41° / 25°3.08.9410.40.2
Mar49° / 32°4.0113.511.72.1
Apr62° / 43°3.910.60.4135.0
May71° / 52°3.711.5014.26.3
Jun81° / 62°4.111.4014.86.0
Jul85° / 67°3.811.2014.65.0
Aug83° / 65°3.710.1013.65.8
Sep76° / 58°4.48.8012.37.0
Oct64° / 46°3.98.90.110.95.8
Nov52° / 36°3.28.10.69.73.0
Dec42° / 29°4.09.42.99.10.4

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 20% of August, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14753
24852
34951
44852
54753
64654
74654
84555
94654
104654
114654
124654
134654
144654
154852
164852
174951
184951
195050
205149
215149
225149
235149
245149
255149
265149
275149
285149
295149
305149
315149

Chance of precipitation in August

Any precipitation

Allentown gets around 3.7 in of rain over 10.1 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 33% and peaks near 37% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
137
236
336
436
535
635
736
836
936
1036
1136
1236
1336
1436
1536
1636
1735
1834
1934
2033
2132
2231
2330
2429
2528
2628
2727
2826
2926
3026
3126

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the muggy band about 27% of days. Sticky, muggy-or-worse air turns up on roughly 35% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
11519272811
21519272811
31619262811
41619262811
51719252811
61719252811
71719252811
81719242811
91819242910
101819242910
111819242910
12181924299
13181925299
14181925299
15181925299
16182025288
17192026288
18192026287
19192026277
20202125277
21202125276
22212225276
23222225266
24232224255
25242324255
26252323245
27252323235
28262322235
29272322225
30282322226
31282421216

Wind in August

Winds average 5 mph in August, the calmest month.

Across August, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 12 min at the start of August to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 72 minutes over August. Sunrise moves from 5:02 AM to 5:32 AM, and sunset from 7:14 PM to 6:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.25:027:14
214.25:037:13
314.15:047:11
414.15:057:10
514.05:067:09
614.05:077:08
714.05:087:07
813.95:097:06
913.95:107:04
1013.95:117:03
1113.85:127:02
1213.85:137:00
1313.75:146:59
1413.75:156:58
1513.75:166:56
1613.65:176:55
1713.65:186:53
1813.55:196:52
1913.55:206:51
2013.55:216:49
2113.45:226:48
2213.45:236:46
2313.35:246:45
2413.35:256:43
2513.35:266:41
2613.25:276:40
2713.25:286:38
2813.15:296:37
2913.15:306:35
3013.05:316:33
3113.05:326:32

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.22 kWh/m².

For context, solar energy here swings from a low near 1.76 kWh/m² to a high of 6.02 kWh/m² in June across the year — August's 5.22 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.6Bright
25.6Bright
35.5Bright
45.5Bright
55.5Bright
65.5Bright
75.4Bright
85.4Bright
95.4Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.2Bright
155.2Bright
165.2Bright
175.2Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.0Bright
245.0Bright
255.0Bright
265.0Bright
274.9Bright
284.9Bright
294.9Bright
304.8Bright
314.8Bright
Planning a trip in August

Is August a good time to visit Allentown?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.8
Sightseeing
4th-best month of the year
6.8
Beach & pool
1st-best month of the year

August is a reasonable time to visit Allentown for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Allentown in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, Allentown sees daytime highs around 83°F and nights near 65°F. Pack light clothes. Worth having: rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

UV index in Allentown in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Allentown peaks around July 10 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 10UV 8Dec 22UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun8Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Allentown in August

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where August falls, not just the annual average.

Air quality in Allentown is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (November, 8 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1417 µg/m³Nov 148 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar13Moderate
Apr13Moderate
May16Moderate
Jun16Moderate
Jul17Moderate
Aug15Moderate
Sep12Good
Oct9Good
Nov8Good
Dec9Good
Location & terrain

Where is Allentown?

Allentown sits at 40.6°N, 75.5°W, 338 ft above sea level, in United States. The nearest listed city is Whitehall Township, 4.3 mi away.

Topography around Allentown

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Allentown.

Within 2 miles, the terrain around Allentown has only modest variations in elevation — a maximum elevation change of 285 ft around an average of 344 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,125 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,516 ft.

The land around Allentown is covered by trees (43%) and artificial surfaces (42%) within 2 miles, trees (47%) and grassland (22%) within 10 miles, and trees (71%) within 50 miles.

2 miles
285 ft
10 miles
1,125 ft
50 miles
2,516 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Whitehall Township 4.3 mi · Bethlehem 6.2 mi · Easton 15 mi · Limerick 26 mi · Pottstown 27 mi · Lansdale 27 mi · Reading 30 mi · Phoenixville 33 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Allentown (40.6084°, -75.4902°, elevation 338 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).