Shirley weather in September

In September, Shirley sees average daytime highs of 71°F and overnight lows near 65°F, with 3.7 in of rain across 8.8 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 74°F in the first days to 67°F by the end. The sky is clear or mostly clear about 43% 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 Shirley's 3rd-clearest and 9th-windiest month. For the whole year in context, see Shirley's year-round climate.

Daytime high
71°
3rd warmest
Overnight low
65°
10th coldest
Rainfall
3.7 in
8.8 wet days
Daylight
12 h 18 min
5:38 AM – 5:54 PM
Cloud cover
52%
3rd clearest
Wind
11 mph
9th windiest
Solar energy
4.53 kWh/m²
Travel score
6.9
out of 10

Shirley is census-designated place in New York, USA.

Density
934/km²
people per km²

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 74°F in the first days to 67°F by the end.

A typical September day in Shirley reaches about 71°F in the afternoon and slips back to 65°F overnight — a 6°F spread between the day's warmth and the night's chill. On most days the high lands between 66°F and 76°F. Set against its neighbours, September runs about 5°F cooler than August and about 9°F warmer than October.

50°60°70°80°151015202530
Avg high (°F)Avg low (°F)
17468
27468
37468
47468
57367
67367
77367
87367
97367
107266
117266
127266
137265
147165
157165
167165
177164
187064
197064
207064
216963
226963
236963
246962
256862
266862
276862
286761
296761
306760

How September really feels in Shirley

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.

Shirley weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan40° / 31°3.79.83.99.40.0
Feb40° / 31°3.49.13.510.40.0
Mar44° / 36°4.410.22.811.70.8
Apr52° / 45°3.610.30.413.12.7
May60° / 53°3.310.2014.24.8
Jun70° / 64°3.38.8014.96.7
Jul76° / 71°3.08.6014.67.2
Aug76° / 70°3.79.3013.67.2
Sep71° / 65°3.78.8012.36.9
Oct62° / 55°4.39010.95.5
Nov53° / 46°3.68.70.39.73.2
Dec45° / 37°4.610.62.29.11.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 43% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16139
26040
36139
46139
56040
66040
76040
86040
95941
105941
115842
125842
135842
145743
155644
165545
175545
185446
195347
205347
215347
225347
235347
245248
255347
265347
275347
285347
295446
305545

Chance of precipitation in September

Any precipitation

Shirley gets around 3.7 in of rain over 8.8 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 28% and peaks near 32% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
125
225
325
425
526
626
726
826
926
1026
1127
1227
1327
1427
1527
1628
1728
1829
1929
2030
2130
2231
2331
2432
2532
2632
2732
2832
2932
3032

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 26% of days. Sticky, muggy-or-worse air turns up on roughly 30% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1919272916
2919272915
31119272914
41219272914
51319262813
61419262812
71519262811
81719262811
91819262710
10191925279
11202025278
12222025277
13232025266
14242025265
15262025255
16272024254
17282024253
18292024243
19312024242
20322023232
21332023221
22342023221
23362122211
24372122201
25382121191
26402121181
27412120170
28432120160
29442120150
30452119140

Wind in September

Winds average 11 mph in September.

Across September, daily wind ranges from about 10 mph on the calmest days to 11 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
110light breeze
210light breeze
310light breeze
410light breeze
510light breeze
610light breeze
710light breeze
810light breeze
910light breeze
1010light breeze
1110light breeze
1210light breeze
1310light breeze
1410light breeze
1511light breeze
1611light breeze
1711light breeze
1811light breeze
1911light breeze
2011light breeze
2111light breeze
2211light breeze
2311light breeze
2411light breeze
2511light breeze
2611light breeze
2711light breeze
2811light breeze
2911light breeze
3011light breeze

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 5:23 AM to 5:52 AM, and sunset from 6:20 PM to 5:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:236:20
212.95:246:18
312.95:256:16
412.85:266:15
512.85:276:13
612.75:286:11
712.75:296:10
812.65:306:08
912.65:316:06
1012.55:326:04
1112.55:336:03
1212.55:346:01
1312.45:355:59
1412.45:365:57
1512.35:375:56
1612.35:385:54
1712.25:395:52
1812.25:405:50
1912.15:415:49
2012.15:425:47
2112.05:435:45
2212.05:445:43
2311.95:455:41
2411.95:465:40
2511.85:475:38
2611.85:485:36
2711.85:495:34
2811.75:505:33
2911.75:515:31
3011.65:525:29

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.53 kWh/m².

For context, solar energy here swings from a low near 1.74 kWh/m² to a high of 6.55 kWh/m² in June across the year — September's 4.53 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.1Bright
45.1Bright
55.0Bright
65.0Bright
74.9Bright
84.9Bright
94.8Bright
104.8Bright
114.8Bright
124.7Bright
134.7Bright
144.6Bright
154.6Bright
164.5Bright
174.5Bright
184.5Bright
194.4Bright
204.3Bright
214.3Bright
224.3Bright
234.2Bright
244.2Bright
254.1Bright
264.0Bright
274.0Bright
284.0Moderate
293.9Moderate
303.9Moderate
Planning a trip in September

Hazard calendar for Shirley

In seasonPeak

In September, Shirley sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Shirley sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Shirley?

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

6.9
Sightseeing
3rd-best month of the year
4.6
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Shirley for sightseeing.

What to pack for Shirley in September

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

In September, Shirley sees daytime highs around 71°F and nights near 65°F. Worth packing: rain gear and sun protection. About 9 days see rain.

rain gearsun protection

Sea temperature near Shirley in September

The nearest coast averages about 69°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 12 mi away) is warmest in August at about 73°F and coldest in February near 40°F.

It's comfortable for a long swim from Jul 4 to Sep 22 — about 2.7 months when the water holds above 68°F.

40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan44Bracing
Feb40Bracing
Mar41Bracing
Apr45Bracing
May53Bracing
Jun64Cool
Jul71Refreshing
Aug73Refreshing
Sep69Refreshing
Oct63Cool
Nov56Bracing
Dec49Bracing

UV index in Shirley 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 Shirley peaks around July 11 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 11UV 8Dec 22UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7Very high
Jun8Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Shirley 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 Shirley is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (November, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1016 µg/m³Nov 178 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar14Moderate
Apr15Moderate
May16Moderate
Jun16Moderate
Jul17Moderate
Aug14Moderate
Sep11Good
Oct9Good
Nov8Good
Dec8Good
Location & terrain

Where is Shirley?

Shirley sits at 40.8°N, 72.9°W, 52 ft above sea level, in United States. The nearest listed city is Mastic, 1.2 mi away.

Topography around Shirley

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

Within 2 miles, the terrain around Shirley has only modest variations in elevation — a maximum elevation change of 118 ft around an average of 49 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 335 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,010 ft.

The land around Shirley is covered by trees (67%) within 2 miles, trees (47%) and water (34%) within 10 miles, and water (58%) and trees (32%) within 50 miles.

2 miles
118 ft
10 miles
335 ft
50 miles
1,010 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Mastic 1.2 mi · Medford 6.8 mi · East Patchogue 6.8 mi · Coram 8.7 mi · Farmingville 8.7 mi · Holtsville 9.3 mi · Selden 9.9 mi · Holbrook 11 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 Shirley (40.8015°, -72.8676°, elevation 52 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).