Lancaster weather in September

In September, Lancaster sees average daytime highs of 76°F and overnight lows near 60°F, with 4.3 in of rain across 9.3 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 36% 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 Lancaster's 2nd-clearest and 9th-windiest month. For the whole year in context, see Lancaster's year-round climate.

Daytime high
76°
4th warmest
Overnight low
60°
9th coldest
Rainfall
4.3 in
9.3 wet days
Daylight
12 h 18 min
5:52 AM – 6:07 PM
Cloud cover
56%
2nd clearest
Wind
6 mph
9th windiest
Solar energy
4.26 kWh/m²
Travel score
6.9
out of 10

Lancaster is city in central Lancaster County, Pennsylvania, United States.

Density
3,116/km²
people per km²
Founded
1730

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

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 Lancaster reaches about 76°F in the afternoon and slips back to 60°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
48064
58064
68063
78063
87962
97962
107862
117862
127861
137761
147760
157760
167660
177659
187659
197558
207558
217458
227457
237457
247357
257356
267356
277255
287255
297155
307154

How September really feels in Lancaster

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.

Lancaster 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°3.19.13.99.50.0
Feb42° / 27°2.993.810.40.3
Mar51° / 34°3.910.32.911.72.4
Apr63° / 45°3.610.30.3135.3
May72° / 55°3.611.4014.26.4
Jun81° / 64°3.711.1014.86.0
Jul85° / 69°3.911.1014.65.1
Aug83° / 67°3.410.3013.65.8
Sep76° / 60°4.39.3012.36.9
Oct65° / 48°3.68.40.110.96.0
Nov53° / 38°3.08.20.49.83.2
Dec44° / 31°3.69.22.39.20.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% 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 48%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15347
25248
35347
45347
55248
65248
75248
85248
95248
105248
115248
125248
135248
145149
155149
165149
175149
185149
195050
205050
215050
225149
235149
245149
255149
265248
275248
285347
295347
305446

Chance of precipitation in September

Any precipitation

Lancaster gets around 4.3 in of rain over 9.3 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 30% and peaks near 32% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
129
229
329
429
529
629
729
829
929
1028
1128
1228
1328
1427
1528
1628
1728
1829
1929
2030
2131
2231
2331
2432
2532
2632
2732
2831
2931
3031

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 20% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1222421259
2232420249
3242420248
4252420238
5272419228
6282419218
7302419208
8312319207
9322318197
10342318187
11352318186
12362218176
13382218175
14392218165
15412219154
16422119154
17432118143
18442118143
19452118133
20472118132
21482118122
22492117122
23512017111
24522017101
25532016101
26541916101
2755191691
2858181590
2958181590
3061171480

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 5:37 AM to 6:06 AM, and sunset from 6:33 PM to 5:43 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:376:33
212.95:386:31
312.85:396:29
412.85:406:28
512.85:416:26
612.75:426:24
712.75:436:23
812.65:446:21
912.65:456:19
1012.55:466:18
1112.55:476:16
1212.45:486:14
1312.45:496:13
1412.35:506:11
1512.35:516:09
1612.35:526:07
1712.25:536:06
1812.25:546:04
1912.15:556:02
2012.15:566:00
2112.05:575:59
2212.05:585:57
2311.95:595:55
2411.96:005:54
2511.96:015:52
2611.86:025:50
2711.86:035:48
2811.76:045:47
2911.76:055:45
3011.66:065:43

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.26 kWh/m².

For context, solar energy here swings from a low near 1.81 kWh/m² to a high of 6.1 kWh/m² in June across the year — September's 4.26 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.7Bright
54.7Bright
64.7Bright
74.6Bright
84.6Bright
94.5Bright
104.5Bright
114.5Bright
124.4Bright
134.4Bright
144.3Bright
154.3Bright
164.3Bright
174.2Bright
184.2Bright
194.2Bright
204.1Bright
214.1Bright
224.0Bright
234.0Moderate
244.0Moderate
253.9Moderate
263.9Moderate
273.8Moderate
283.8Moderate
293.8Moderate
303.7Moderate
Planning a trip in September

Is September a good time to visit Lancaster?

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 Lancaster for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Lancaster in September

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

In September, Lancaster sees daytime highs around 76°F and nights near 60°F. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

UV index in Lancaster 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 Lancaster peaks around June 23 at about 9 (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 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 23UV 9Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug6High
Sep6High
Oct3Moderate
Nov3Moderate
Dec2Low

Air quality in Lancaster 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 Lancaster 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 138 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar13Moderate
Apr13Moderate
May15Moderate
Jun16Moderate
Jul17Moderate
Aug15Moderate
Sep12Good
Oct9Good
Nov8Good
Dec9Good
Location & terrain

Where is Lancaster?

Lancaster sits at 40.0°N, 76.3°W, 361 ft above sea level, in United States. The nearest listed city is Lebanon, 22 mi away.

Topography around Lancaster

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

Within 2 miles, the terrain around Lancaster has only modest variations in elevation — a maximum elevation change of 246 ft around an average of 348 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 725 ft; within 50 miles, large variations in elevation — a maximum elevation change of 1,991 ft.

The land around Lancaster is covered by trees (48%) and artificial surfaces (35%) within 2 miles, cropland (33%), trees (31%) and grassland (26%) within 10 miles, and trees (55%) within 50 miles.

2 miles
246 ft
10 miles
725 ft
50 miles
1,991 ft
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Lebanon 22 mi · York 23 mi · Reading 29 mi · Bel Air North 34 mi · North Bel Air 35 mi · Harrisburg 35 mi · South Bel Air 35 mi · Bel Air South 37 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 Lancaster (40.0379°, -76.3055°, elevation 361 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).