Carlisle weather in September

In September, Carlisle sees average daytime highs of 76°F and overnight lows near 58°F, with 4.4 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 80°F in the first days to 71°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 Carlisle's 2nd-clearest and 9th-windiest month. For the whole year in context, see Carlisle's year-round climate.

Daytime high
76°
4th warmest
Overnight low
58°
9th coldest
Rainfall
4.4 in
9.3 wet days
Daylight
12 h 18 min
5:55 AM – 6:11 PM
Cloud cover
56%
2nd clearest
Wind
5 mph
9th windiest
Solar energy
4.19 kWh/m²
Travel score
6.9
out of 10

Carlisle is borough in Cumberland County, Pennsylvania, United States.

Density
1,334/km²
people per km²
Founded
1751

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 80°F in the first days to 71°F by the end.

A typical September day in Carlisle reaches about 76°F in the afternoon and slips back to 58°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 66°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)
18063
28062
38062
48062
57962
67961
77961
87861
97860
107860
117760
127759
137759
147658
157658
167558
177557
187557
197456
207456
217456
227355
237355
247255
257254
267254
277153
287153
297053
307052

How September really feels in Carlisle

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.

Carlisle 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
Jan38° / 24°3.29.24.59.50.0
Feb40° / 25°2.894.410.40.2
Mar50° / 33°3.910.73.311.72.1
Apr62° / 43°3.711.20.3135.0
May71° / 53°3.812.7014.26.1
Jun80° / 62°3.711.6014.86.2
Jul84° / 67°3.910.8014.65.3
Aug82° / 65°3.410.6013.66.0
Sep76° / 58°4.49.3012.36.9
Oct64° / 46°3.48.30.210.95.8
Nov52° / 37°3.18.50.89.82.8
Dec42° / 29°3.4939.20.3

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 17% of September, with mostly cloudy or overcast conditions the remaining 48%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15347
25347
35347
45446
55347
65347
75347
85248
95347
105347
115347
125248
135248
145248
155149
165248
175248
185149
195149
205149
215149
225149
235149
245149
255149
265248
275248
285248
295248
305347

Chance of precipitation in September

Any precipitation

Carlisle gets around 4.4 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
1029
1129
1228
1328
1428
1529
1629
1729
1830
1930
2031
2131
2232
2332
2432
2532
2632
2732
2832
2932
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 46% of days. Sticky, muggy-or-worse air turns up on roughly 14% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1262622234
2272621224
3292620214
4302620204
5322619204
6332619194
7352518184
8362518173
9372518173
10392418163
11402418152
12412418152
13432318142
14442318132
15452218131
16472218121
17482118111
18492118111
19502118101
2052211890
2153201890
2255201780
2355201780
2457191770
2559191660
2660181660
2760181660
2863171550
2963171550
3064161550

Wind in September

Winds average 5 mph in September.

Across September, 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.

0246810151015202530
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
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 5:40 AM to 6:09 AM, and sunset from 6:36 PM to 5:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:406:36
212.95:416:35
312.85:426:33
412.85:436:31
512.85:446:30
612.75:456:28
712.75:466:26
812.65:476:25
912.65:486:23
1012.55:496:21
1112.55:506:20
1212.45:516:18
1312.45:526:16
1412.45:536:14
1512.35:546:13
1612.35:556:11
1712.25:566:09
1812.25:576:07
1912.15:586:06
2012.15:596:04
2112.06:006:02
2212.06:016:01
2311.96:025:59
2411.96:035:57
2511.96:045:55
2611.86:055:54
2711.86:065:52
2811.76:075:50
2911.76:085:49
3011.66:095:47

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.19 kWh/m².

For context, solar energy here swings from a low near 1.72 kWh/m² to a high of 6.05 kWh/m² in June across the year — September's 4.19 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.7Bright
34.7Bright
44.7Bright
54.6Bright
64.6Bright
74.5Bright
84.5Bright
94.5Bright
104.4Bright
114.4Bright
124.3Bright
134.3Bright
144.3Bright
154.2Bright
164.2Bright
174.2Bright
184.1Bright
194.1Bright
204.0Bright
214.0Bright
224.0Moderate
233.9Moderate
243.9Moderate
253.8Moderate
263.8Moderate
273.8Moderate
283.7Moderate
293.7Moderate
303.6Moderate
Planning a trip in September

Is September a good time to visit Carlisle?

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
5.8
Beach & pool
4th-best month of the year

September is a reasonable time to visit Carlisle for sightseeing.

What to pack for Carlisle in September

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

In September, Carlisle sees daytime highs around 76°F and nights near 58°F. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

UV index in Carlisle 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 Carlisle peaks around June 22 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 1 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 22UV 9Dec 20UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Carlisle 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 Carlisle 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 1316 µg/m³Nov 118 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar12Moderate
Apr13Moderate
May14Moderate
Jun16Moderate
Jul17Moderate
Aug14Moderate
Sep11Good
Oct8Good
Nov8Good
Dec9Good
Location & terrain

Where is Carlisle?

Carlisle sits at 40.2°N, 77.2°W, 479 ft above sea level, in United States. The nearest listed city is Harrisburg, 17 mi away.

Topography around Carlisle

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

Within 2 miles, the terrain around Carlisle has only modest variations in elevation — a maximum elevation change of 180 ft around an average of 482 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,699 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,438 ft.

The land around Carlisle is covered by trees (37%), grassland (27%) and artificial surfaces (27%) within 2 miles, trees (50%), cropland (24%) and grassland (21%) within 10 miles, and trees (60%) and cropland (21%) within 50 miles.

2 miles
180 ft
10 miles
1,699 ft
50 miles
2,438 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Harrisburg 17 mi · York 29 mi · Hanover 30 mi · Chambersburg 31 mi · Lebanon 42 mi · Westminster 45 mi · Hagerstown 48 mi · Lancaster 48 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 Carlisle (40.2015°, -77.1889°, elevation 479 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).