Hempstead weather in September

In September, Hempstead sees average daytime highs of 71°F and overnight lows near 64°F, with 3.8 in of rain across 9.2 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 75°F in the first days to 68°F by the end. The sky is clear or mostly clear about 41% 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 Hempstead's 2nd-clearest and 8th-windiest month. For the whole year in context, see Hempstead's year-round climate.

Daytime high
71°
4th warmest
Overnight low
64°
9th coldest
Rainfall
3.8 in
9.2 wet days
Daylight
12 h 18 min
5:41 AM – 5:57 PM
Cloud cover
53%
2nd clearest
Wind
9 mph
8th windiest
Solar energy
4.35 kWh/m²
Travel score
6.9
out of 10

Hempstead is town in Nassau County, New York, United States, suburb of NYC.

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 75°F in the first days to 68°F by the end.

A typical September day in Hempstead reaches about 71°F in the afternoon and slips back to 64°F overnight — a 7°F spread between the day's warmth and the night's chill. On most days the high lands between 66°F and 77°F. Set against its neighbours, September runs about 6°F cooler than August and about 10°F warmer than October.

50°60°70°80°151015202530
Avg high (°F)Avg low (°F)
17568
27568
37568
47567
57467
67467
77467
87466
97366
107366
117365
127365
137265
147265
157264
167164
177164
187164
197163
207063
217063
227062
236962
246962
256961
266961
276861
286860
296760
306760

How September really feels in Hempstead

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.

Hempstead 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
Jan38° / 29°3.79.83.99.40.0
Feb39° / 29°3.59.23.710.40.0
Mar44° / 35°4.610.43.111.70.8
Apr53° / 44°3.910.80.313.12.9
May62° / 54°3.510.9014.25.2
Jun72° / 64°3.710.3014.96.5
Jul78° / 71°3.59.9014.66.9
Aug77° / 70°4.09.8013.67.0
Sep71° / 64°3.89.2012.36.9
Oct62° / 54°4.49010.95.5
Nov52° / 44°3.68.90.39.72.9
Dec44° / 35°4.710.52.49.10.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 41% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 45%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15743
25743
35743
45743
55644
65644
75644
85644
95644
105644
115644
125644
135545
145644
155545
165446
175446
185347
195347
205248
215248
225248
235248
245248
255248
265347
275347
285446
295446
305446

Chance of precipitation in September

Any precipitation

Hempstead gets around 3.8 in of rain over 9.2 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 29% and peaks near 32% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
126
226
326
427
527
627
727
828
928
1028
1128
1229
1329
1429
1529
1629
1729
1830
1930
2031
2131
2231
2332
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 28% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1819283015
2919283015
31019282915
41119282814
51219282813
61319282713
71519282712
81619282611
91719282610
10191928259
11201927258
12221927258
13231927247
14242027246
15262026235
16272026224
17282126224
18292126213
19302126202
20322225192
21332225192
22342324181
23352323171
24372423161
25382422151
26392421151
27412420141
28422420131
29442419130
30452418120

Wind in September

Winds average 9 mph in September.

Across September, daily wind ranges from about 9 mph on the calmest days to 10 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
19light breeze
29light breeze
39light breeze
49light breeze
59light breeze
69light breeze
79light breeze
89light breeze
99light breeze
109light breeze
119light breeze
129light breeze
139light breeze
149light breeze
159light breeze
169light breeze
179light breeze
189light breeze
199light breeze
209light breeze
219light breeze
229light breeze
239light breeze
249light breeze
2510light breeze
2610light breeze
2710light breeze
2810light breeze
2910light breeze
3010light breeze

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 5:26 AM to 5:55 AM, and sunset from 6:23 PM to 5:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:266:23
212.95:276:21
312.95:286:19
412.85:296:18
512.85:306:16
612.75:316:14
712.75:326:12
812.65:336:11
912.65:346:09
1012.55:356:07
1112.55:366:06
1212.55:376:04
1312.45:386:02
1412.45:396:00
1512.35:405:59
1612.35:415:57
1712.25:425:55
1812.25:435:53
1912.15:445:51
2012.15:455:50
2112.05:465:48
2212.05:475:46
2311.95:485:44
2411.95:495:43
2511.85:505:41
2611.85:515:39
2711.85:525:38
2811.75:535:36
2911.75:545:34
3011.65:555:32

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.35 kWh/m².

For context, solar energy here swings from a low near 1.75 kWh/m² to a high of 6.23 kWh/m² in June across the year — September's 4.35 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
15.0Bright
24.9Bright
34.9Bright
44.9Bright
54.8Bright
64.8Bright
74.7Bright
84.7Bright
94.6Bright
104.6Bright
114.6Bright
124.5Bright
134.5Bright
144.4Bright
154.4Bright
164.3Bright
174.3Bright
184.3Bright
194.2Bright
204.2Bright
214.1Bright
224.1Bright
234.0Bright
244.0Moderate
253.9Moderate
263.9Moderate
273.9Moderate
283.8Moderate
293.8Moderate
303.7Moderate
Planning a trip in September

Hazard calendar for Hempstead

In seasonPeak

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

Hempstead 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 Hempstead?

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

6.9
Sightseeing
2nd-best month of the year
4.8
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Hempstead for sightseeing.

What to pack for Hempstead in September

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

In September, Hempstead sees daytime highs around 71°F and nights near 64°F. Worth packing: rain gear. About 9 days see rain.

rain gear

Sea temperature near Hempstead in September

The nearest coast averages about 70°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 73°F and coldest in February near 40°F.

It's comfortable for a long swim from Jun 30 to Sep 25 — about 2.9 months when the water holds above 68°F.

40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°F)Comfort
Jan43Bracing
Feb40Bracing
Mar40Bracing
Apr46Bracing
May55Bracing
Jun65Cool
Jul72Refreshing
Aug73Refreshing
Sep70Refreshing
Oct63Cool
Nov55Bracing
Dec48Bracing

UV index in Hempstead 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 Hempstead 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 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery 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 Hempstead 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 Hempstead is worst in July — around 19 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (November, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1018 µg/m³Nov 169 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb13Moderate
Mar15Moderate
Apr16Moderate
May18Moderate
Jun18Moderate
Jul19Moderate
Aug16Moderate
Sep13Moderate
Oct10Good
Nov9Good
Dec10Good
Location & terrain

Where is Hempstead?

Hempstead sits at 40.7°N, 73.6°W, 56 ft above sea level, in United States. The nearest listed city is Uniondale, 1.2 mi away.

Topography around Hempstead

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

Within 2 miles, the terrain around Hempstead has only modest variations in elevation — a maximum elevation change of 118 ft around an average of 72 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 400 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,663 ft.

The land around Hempstead is covered by artificial surfaces (53%) and trees (32%) within 2 miles, artificial surfaces (42%) and trees (30%) within 10 miles, and trees (42%) and water (41%) within 50 miles.

2 miles
118 ft
10 miles
400 ft
50 miles
1,663 ft
treesgrasslandartificial surfacesbare terrainwaterwetland
September weather nearby: Uniondale 1.2 mi · Garden City 1.9 mi · West Hempstead 1.9 mi · Roosevelt 2.5 mi · Franklin Square 3.1 mi · East Meadow 3.1 mi · Mineola 3.1 mi · Baldwin 3.7 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 Hempstead (40.7062°, -73.6187°, elevation 56 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).