Radnor weather in August

In August, Radnor sees average daytime highs of 84°F and overnight lows near 68°F, with 3.7 in of rain across 10.3 wet days and about 13.6 hours of daylight. It is the 2nd-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 85°F in the first days to 83°F by the end. The sky is clear or mostly clear about 30% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 h 06 min at the start of August to 13 hours by month's end. Set against the rest of the year, August is Radnor's 4th-clearest and 12th-windiest month. For the whole year in context, see Radnor's year-round climate.

Daytime high
84°
2nd warmest
Overnight low
68°
11th coldest
Rainfall
3.7 in
10.3 wet days
Daylight
13 h 36 min
5:18 AM – 6:53 PM
Cloud cover
58%
4th clearest
Wind
5 mph
12th windiest
Solar energy
5.24 kWh/m²
Travel score
5.5
out of 10

Radnor is unincorporated community in Radnor Township, Pennsylvania, United States.

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 83°F by the end.

A typical August day in Radnor reaches about 84°F in the afternoon and slips back to 68°F overnight — a 16°F spread between the day's warmth and the night's chill. On most days the high lands between 77°F and 91°F. Set against its neighbours, August runs about 2°F cooler than July and about 7°F warmer than September.

60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18670
28670
38570
48569
58569
68569
78569
88569
98569
108569
118569
128569
138469
148468
158468
168468
178468
188468
198468
208468
218467
228367
238367
248367
258367
268367
278367
288366
298366
308266
318266

How August really feels in Radnor

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.

Radnor weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan40° / 27°3.29.33.89.50.0
Feb43° / 28°3.08.93.410.40.6
Mar52° / 35°4.110.52.611.72.7
Apr64° / 46°3.610.20.3135.5
May73° / 55°3.511.1014.26.5
Jun82° / 64°3.810.7014.85.9
Jul86° / 70°3.910.7014.64.8
Aug84° / 68°3.710.3013.65.5
Sep78° / 61°4.19.2012.36.9
Oct66° / 49°3.68.2010.96.3
Nov55° / 39°2.97.80.39.83.6
Dec45° / 32°3.99.31.99.21.1

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% 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%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14852
24852
34852
44852
54852
64951
74951
84852
94852
104852
114753
124753
134753
144852
154852
164852
174951
184951
194951
205050
215050
225050
235149
245149
255248
265248
275149
285248
295248
305347
315347

Chance of precipitation in August

Any precipitation

Radnor gets around 3.7 in of rain over 10.3 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 34% and peaks near 38% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
138
238
338
438
538
638
738
838
938
1038
1138
1238
1337
1437
1536
1636
1735
1834
1933
2032
2131
2230
2329
2428
2528
2627
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 30% of days. Sticky, muggy-or-worse air turns up on roughly 47% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1914223222
21014223221
31014233221
41113233221
51113233121
61213233121
71213233121
81213233121
91213233220
101213233220
111213233219
121213233318
131314233318
141314233317
151315233317
161315233316
171316233216
181316233215
191317243215
201417243114
211417243114
221518243013
231518243013
241619242913
251619232813
261719232713
271820232613
281820232513
291920232513
301921232413
312021222413

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 6 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
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 06 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 66 minutes over August. Sunrise moves from 5:03 AM to 5:32 AM, and sunset from 7:12 PM to 6:31 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.15:037:12
214.15:047:11
314.15:057:10
414.05:067:09
514.05:077:07
614.05:087:06
713.95:097:05
813.95:107:04
913.95:117:03
1013.85:127:01
1113.85:137:00
1213.85:146:59
1313.75:156:57
1413.75:166:56
1513.65:176:55
1613.65:186:53
1713.65:196:52
1813.55:206:51
1913.55:216:49
2013.45:226:48
2113.45:236:46
2213.45:246:45
2313.35:256:43
2413.35:266:42
2513.25:266:40
2613.25:276:39
2713.15:286:37
2813.15:296:35
2913.15:306:34
3013.05:316:32
3113.05:326:31

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.24 kWh/m².

For context, solar energy here swings from a low near 1.82 kWh/m² to a high of 6.03 kWh/m² in June across the year — August's 5.24 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.6Bright
25.5Bright
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
185.2Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.1Bright
245.0Bright
255.0Bright
265.0Bright
275.0Bright
284.9Bright
294.9Bright
304.9Bright
314.8Bright
Planning a trip in August

Is August a good time to visit Radnor?

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

5.5
Sightseeing
5th-best month of the year
6.9
Beach & pool
1st-best month of the year

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

What to pack for Radnor in August

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

In August, Radnor sees daytime highs around 84°F and nights near 68°F. Pack light clothes. Worth having: rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

UV index in Radnor 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 Radnor peaks around July 10 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 10UV 8Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun8Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov3Moderate
Dec2Low

Air quality in Radnor 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 Radnor is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (November, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1317 µg/m³Nov 129 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb13Moderate
Mar15Moderate
Apr13Moderate
May15Moderate
Jun16Moderate
Jul18Moderate
Aug15Moderate
Sep12Good
Oct9Good
Nov9Good
Dec10Good
Location & terrain

Where is Radnor?

Radnor sits at 40.0°N, 75.4°W, 433 ft above sea level, in United States. The nearest listed city is Wayne, 1.2 mi away.

Topography around Radnor

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

Within 2 miles, the terrain around Radnor has only modest variations in elevation — a maximum elevation change of 423 ft around an average of 397 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 981 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,913 ft.

The land around Radnor is covered by trees (80%) within 2 miles, trees (67%) within 10 miles, and trees (58%) within 50 miles.

2 miles
423 ft
10 miles
981 ft
50 miles
1,913 ft
treesgrasslandcroplandartificial surfaceswaterwetland
August weather nearby: Wayne 1.2 mi · King of Prussia 3.7 mi · Havertown 5.0 mi · Norristown 5.6 mi · Overbrook 7.5 mi · Drexel Hill 7.5 mi · Springfield 8.1 mi · Haddington 8.7 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 Radnor (40.0462°, -75.3599°, elevation 433 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).