Lansdale weather in September

In September, Lansdale sees average daytime highs of 76°F and overnight lows near 59°F, with 4.4 in of rain across 9.7 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 1st-wettest month of the year here.

Highs ease over the month, from about 81°F in the first days to 72°F by the end. The sky is clear or mostly clear about 35% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Lansdale's 2nd-clearest and 9th-windiest month. For the whole year in context, see Lansdale's year-round climate.

Daytime high
76°
4th warmest
Overnight low
59°
9th coldest
Rainfall
4.4 in
9.7 wet days
Daylight
12 h 18 min
5:48 AM – 6:03 PM
Cloud cover
56%
2nd clearest
Wind
6 mph
9th windiest
Solar energy
4.22 kWh/m²
Travel score
6.9
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 81°F in the first days to 72°F by the end.

A typical September day in Lansdale reaches about 76°F in the afternoon and slips back to 59°F overnight — a 17°F spread between the day's warmth and the night's chill. On most days the high lands between 67°F and 85°F. Set against its neighbours, September runs about 7°F cooler than August and about 12°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18164
28164
38164
48063
58063
68063
77962
87962
97962
107862
117861
127861
137760
147760
157760
167659
177659
187658
197558
207558
217457
227457
237457
247356
257356
267356
277255
287255
297155
307154

How September really feels in Lansdale

Once humidity and wind are folded in, September 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

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

Lansdale weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan39° / 26°3.39.349.50.0
Feb42° / 27°3.08.83.510.40.4
Mar51° / 34°4.110.9311.72.4
Apr62° / 44°3.810.90.4135.1
May72° / 54°3.911.6014.26.3
Jun81° / 63°4.311.5014.86.0
Jul85° / 68°4.411.4014.65.0
Aug83° / 67°4.010.5013.65.8
Sep76° / 59°4.49.7012.36.9
Oct65° / 48°3.78.70.110.96.0
Nov53° / 38°3.07.80.59.83.3
Dec44° / 31°4.09.32.39.20.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 50%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15149
25149
35050
45149
55149
65050
75050
85149
95149
105149
115149
125149
135149
145149
155050
165050
175050
184951
194951
204951
214951
224951
234951
244951
255050
265050
275050
285050
295149
305149

Chance of precipitation in September

Any precipitation

Lansdale gets around 4.4 in of rain over 9.7 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 31% and peaks near 33% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
128
229
329
429
530
630
730
830
930
1030
1130
1230
1330
1430
1530
1631
1731
1831
1932
2032
2133
2233
2333
2433
2533
2633
2733
2833
2933
3033

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 41% of days. Sticky, muggy-or-worse air turns up on roughly 19% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
12324212210
22423212210
32523212110
42623212010
5282320209
6292320199
7302320189
8312220188
9332220178
10342220177
11352121167
12362121166
13382121155
14392121155
15402021144
16422021144
17432020133
18442020133
19452020132
20462020122
21482019122
22491919122
23511918111
24521917111
25531917101
26551816101
2756181691
2858171591
2958171591
3061161481

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over September. Sunrise moves from 5:33 AM to 6:02 AM, and sunset from 6:29 PM to 5:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:336:29
212.95:346:27
312.85:356:26
412.85:366:24
512.85:376:22
612.75:386:20
712.75:396:19
812.65:406:17
912.65:416:15
1012.55:426:14
1112.55:436:12
1212.45:446:10
1312.45:456:09
1412.45:466:07
1512.35:476:05
1612.35:486:03
1712.25:496:02
1812.25:506:00
1912.15:515:58
2012.15:525:56
2112.05:535:55
2212.05:545:53
2311.95:555:51
2411.95:565:49
2511.95:575:48
2611.85:585:46
2711.85:595:44
2811.76:005:43
2911.76:015:41
3011.66:025:39

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.22 kWh/m².

For context, solar energy here swings from a low near 1.79 kWh/m² to a high of 6.02 kWh/m² in June across the year — September's 4.22 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.7Bright
44.7Bright
54.6Bright
64.6Bright
74.6Bright
84.5Bright
94.5Bright
104.5Bright
114.4Bright
124.4Bright
134.3Bright
144.3Bright
154.3Bright
164.2Bright
174.2Bright
184.2Bright
194.1Bright
204.1Bright
214.0Bright
224.0Moderate
233.9Moderate
243.9Moderate
253.9Moderate
263.8Moderate
273.8Moderate
283.7Moderate
293.7Moderate
303.7Moderate
Planning a trip in September

Is September a good time to visit Lansdale?

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

6.9
Sightseeing
1st-best month of the year
6.0
Beach & pool
4th-best month of the year

September is a reasonable time to visit Lansdale for sightseeing.

What to pack for Lansdale in September

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

In September, Lansdale sees daytime highs around 76°F and nights near 59°F. Worth packing: light clothes and rain gear. About 10 days see rain.

light clothesrain gear

UV index in Lansdale in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September 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 Lansdale 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
Nov2Moderate
Dec2Low

Air quality in Lansdale in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Lansdale 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 1518 µg/m³Nov 149 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb13Moderate
Mar14Moderate
Apr14Moderate
May16Moderate
Jun17Moderate
Jul18Moderate
Aug15Moderate
Sep13Moderate
Oct10Good
Nov9Good
Dec10Good
Location & terrain

Where is Lansdale?

Lansdale sits at 40.2°N, 75.3°W, 358 ft above sea level, in United States. The nearest listed city is Norristown, 8.7 mi away.

Topography around Lansdale

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

Within 2 miles, the terrain around Lansdale has only modest variations in elevation — a maximum elevation change of 236 ft around an average of 358 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 814 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,962 ft.

The land around Lansdale is covered by trees (62%) and artificial surfaces (22%) within 2 miles, trees (61%) and grassland (25%) within 10 miles, and trees (63%) within 50 miles.

2 miles
236 ft
10 miles
814 ft
50 miles
1,962 ft
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Norristown 8.7 mi · Willow Grove 11 mi · King of Prussia 12 mi · Abington 12 mi · Limerick 12 mi · East Mount Airy 13 mi · West Oak Lane 14 mi · Radnor 14 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 Lansdale (40.2415°, -75.2838°, elevation 358 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).