New Castle weather in September

In September, New Castle sees average daytime highs of 73°F and overnight lows near 55°F, with 4.0 in of rain across 10.2 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 77°F in the first days to 69°F by the end. The sky is clear or mostly clear about 34% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is New Castle's 1st-clearest and 9th-windiest month. For the whole year in context, see New Castle's year-round climate.

Daytime high
73°
4th warmest
Overnight low
55°
9th coldest
Rainfall
4.0 in
10.2 wet days
Daylight
12 h 18 min
6:08 AM – 6:24 PM
Cloud cover
56%
1st clearest
Wind
6 mph
9th windiest
Solar energy
4.19 kWh/m²
Travel score
6.7
out of 10

New Castle is city in and the county seat of Lawrence County, Pennsylvania, United States.

Density
1,012/km²
people per km²
Founded
1802

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 77°F in the first days to 69°F by the end.

A typical September day in New Castle reaches about 73°F in the afternoon and slips back to 55°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 63°F and 83°F. Set against its neighbours, September runs about 6°F cooler than August and about 12°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
17859
27759
37759
47759
57758
67658
77658
87657
97557
107557
117556
127456
137456
147455
157355
167355
177354
187254
197253
207253
217153
227152
237152
247052
257051
266951
276951
286950
296850
306850

How September really feels in New Castle

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.

New Castle weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan35° / 21°3.612.88.69.40.0
Feb38° / 22°2.810.96.610.40.0
Mar47° / 30°4.012.74.411.71.4
Apr60° / 41°4.614.21.513.14.2
May69° / 50°4.414.2014.35.7
Jun77° / 59°4.813.5014.96.2
Jul81° / 63°4.113.3014.66.0
Aug80° / 62°3.711013.66.5
Sep73° / 55°4.010.2012.36.7
Oct61° / 44°3.611.40.210.94.9
Nov49° / 34°3.510.72.39.71.9
Dec39° / 27°3.511.95.79.10.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 49%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15644
25644
35644
45644
55545
65446
75446
85446
95248
105248
115149
125149
135050
145050
155050
165050
175050
184951
194951
204951
214951
224951
234951
244951
254951
264951
274951
284951
294951
305050

Chance of precipitation in September

Any precipitation

New Castle gets around 4.0 in of rain over 10.2 wet days in September. 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 36% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
132
232
332
432
532
633
733
833
933
1033
1133
1233
1333
1433
1533
1633
1733
1833
1933
2034
2134
2234
2335
2435
2535
2636
2736
2836
2936
3036

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 47% of days. Sticky, muggy-or-worse air turns up on roughly 11% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1262525203
2272525203
3282624193
4292624183
5302623173
6322722163
7332722153
8342721153
9362721142
10372721132
11392720122
12402720112
13412620112
14432619101
1545261991
1647251981
1748251881
1850241871
1952231870
2055221760
2157211750
2259201650
2360191650
2463181540
2563181540
2665171440
2767161340
2867161340
2969151240
3071141140

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 7 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
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours 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 84 minutes over September. Sunrise moves from 5:52 AM to 6:22 AM, and sunset from 6:50 PM to 5:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:526:50
212.95:536:48
312.95:546:46
412.85:556:45
512.85:566:43
612.75:576:41
712.75:586:40
812.65:596:38
912.66:006:36
1012.56:026:34
1112.56:036:33
1212.56:046:31
1312.46:056:29
1412.46:066:27
1512.36:076:26
1612.36:086:24
1712.26:096:22
1812.26:106:20
1912.16:116:18
2012.16:126:17
2112.06:136:15
2212.06:146:13
2311.96:156:11
2411.96:166:10
2511.86:176:08
2611.86:186:06
2711.86:196:04
2811.76:206:03
2911.76:216:01
3011.66:225:59

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 1.44 kWh/m² to a high of 5.96 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
44.6Bright
54.6Bright
64.6Bright
74.5Bright
84.5Bright
94.4Bright
104.4Bright
114.4Bright
124.3Bright
134.3Bright
144.3Bright
154.2Bright
164.2Bright
174.1Bright
184.1Bright
194.1Bright
204.0Bright
214.0Moderate
224.0Moderate
233.9Moderate
243.9Moderate
253.8Moderate
263.8Moderate
273.7Moderate
283.7Moderate
293.7Moderate
303.6Moderate
Planning a trip in September

Is September a good time to visit New Castle?

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

6.7
Sightseeing
1st-best month of the year
5.1
Beach & pool
4th-best month of the year

September is a reasonable time to visit New Castle for sightseeing.

What to pack for New Castle in September

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

In September, New Castle sees daytime highs around 73°F and nights near 55°F. Worth packing: light clothes and rain gear. About 10 days see rain.

light clothesrain gear

UV index in New Castle 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 New Castle peaks around June 22 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 22UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug7Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in New Castle 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 New Castle is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (November, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1216 µg/m³Nov 137 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar11Good
Apr11Good
May14Moderate
Jun15Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct7Good
Nov7Good
Dec8Good
Location & terrain

Where is New Castle?

New Castle sits at 41.0°N, 80.3°W, 853 ft above sea level, in United States. The nearest listed city is Boardman, 17 mi away.

Topography around New Castle

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

Within 2 miles, the terrain around New Castle has only modest variations in elevation — a maximum elevation change of 430 ft around an average of 988 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 732 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,089 ft.

The land around New Castle is covered by trees (56%), grassland (22%) and artificial surfaces (20%) within 2 miles, trees (58%) and grassland (25%) within 10 miles, and trees (69%) within 50 miles.

2 miles
430 ft
10 miles
732 ft
50 miles
1,089 ft
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Boardman 17 mi · Hermitage 17 mi · Youngstown 17 mi · Austintown 23 mi · Niles 25 mi · Cranberry Township 25 mi · Warren 29 mi · Allison Park 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 New Castle (41.0037°, -80.347°, elevation 853 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).