Charlotte Amalie weather in September

In September, Charlotte Amalie sees average daytime highs of 28°C and overnight lows near 27°C, with 133 mm of rain across 17.7 wet days and about 12.1 hours of daylight. It is the 1st-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 35% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 h 24 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Charlotte Amalie's 12th-clearest and 11th-windiest month. For the whole year in context, see Charlotte Amalie's year-round climate.

Daytime high
28°
1st warmest
Overnight low
27°
11th coldest
Rainfall
133 mm
17.7 wet days
Daylight
12 h 06 min
6:11 AM – 6:17 PM
Cloud cover
58%
12th clearest
Wind
21 km/h
11th windiest
Solar energy
5.86 kWh/m²
Travel score
4.8
out of 10

Charlotte Amalie is capital and largest city of the United States Virgin Islands.

Density
6,369/km²
people per km²
Founded
1666

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 28°C through the month.

A typical September day in Charlotte Amalie reaches about 28°C in the afternoon and slips back to 27°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 29°C. Set against its neighbours, September runs on par with August and on par with October.

24°26°28°30°32°151015202530
Avg high (°C)Avg low (°C)
12827
22827
32827
42827
52827
62827
72827
82827
92827
102827
112827
122827
132827
142827
152827
162827
172827
182827
192827
202827
212827
222827
232827
242827
252826
262826
272826
282826
292826
302826

How September really feels in Charlotte Amalie

Once humidity and wind are folded in, September averages 30 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
30
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Charlotte Amalie weather by month

How September compares with the rest of the year at a glance. September is the 1st-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan26° / 24°288.7117.5
Feb25° / 24°206.611.47.8
Mar25° / 24°215.911.97.9
Apr26° / 25°357.812.47.4
May27° / 26°751312.96.2
Jun28° / 26°5711.813.16.1
Jul28° / 26°8015.5135.8
Aug28° / 27°1021712.65.1
Sep28° / 27°13317.712.14.8
Oct28° / 26°1271811.65.3
Nov27° / 26°11916.411.15.7
Dec26° / 25°4711.510.96.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 48%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15347
25347
35347
45347
55347
65446
75446
85446
95446
105347
115347
125446
135347
145347
155347
165248
175248
185248
195149
205149
215149
225050
235050
245050
255149
265149
275149
285149
295149
305248

Chance of precipitation in September

Any precipitation

Charlotte Amalie gets around 133 mm of rain over 17.7 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 59% and peaks near 61% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
157
257
357
457
557
657
757
857
957
1058
1158
1258
1359
1459
1559
1659
1760
1860
1960
2061
2161
2261
2361
2461
2561
2660
2760
2860
2960
3060

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the miserable band about 58% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
13565
23565
33565
43565
53565
63664
73664
83664
93664
103664
113763
123763
133862
143862
153961
164060
174060
184159
194258
204357
214555
224654
234753
244852
254951
265050
275248
285347
295446
305644

Wind in September

Winds average 21 km/h in September.

Across September, daily wind ranges from about 20 km/h on the calmest days to 22 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
122breezy
222breezy
322breezy
422breezy
522breezy
622breezy
722breezy
822breezy
922breezy
1022breezy
1122breezy
1222breezy
1322breezy
1421breezy
1521breezy
1621breezy
1721breezy
1821breezy
1921breezy
2021breezy
2121breezy
2221breezy
2321breezy
2421breezy
2520breezy
2620breezy
2720breezy
2820breezy
2920breezy
3020breezy

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 24 min at the start of September to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 30 minutes over September. Sunrise moves from 6:08 AM to 6:13 AM, and sunset from 6:30 PM to 6:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.46:086:30
212.36:096:30
312.36:096:29
412.36:096:28
512.36:096:27
612.36:096:26
712.36:106:25
812.26:106:24
912.26:106:23
1012.26:106:23
1112.26:106:22
1212.26:106:21
1312.26:106:20
1412.16:116:19
1512.16:116:18
1612.16:116:17
1712.16:116:16
1812.16:116:15
1912.06:116:14
2012.06:126:13
2112.06:126:13
2212.06:126:12
2312.06:126:11
2412.06:126:10
2511.96:126:09
2611.96:136:08
2711.96:136:07
2811.96:136:06
2911.96:136:05
3011.96:136:05

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.86 kWh/m².

For context, solar energy here swings from a low near 4.46 kWh/m² to a high of 6.63 kWh/m² in April across the year — September's 5.86 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.1Intense
26.1Intense
36.1Intense
46.1Intense
56.1Intense
66.1Intense
76.0Intense
86.0Intense
96.0Intense
106.0Bright
116.0Bright
125.9Bright
135.9Bright
145.9Bright
155.9Bright
165.8Bright
175.8Bright
185.8Bright
195.8Bright
205.7Bright
215.7Bright
225.7Bright
235.7Bright
245.7Bright
255.6Bright
265.6Bright
275.6Bright
285.6Bright
295.6Bright
305.5Bright
Planning a trip in September

Hazard calendar for Charlotte Amalie

In seasonPeak

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

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

Charlotte Amalie's rainy season runs May–May, when most of the year's rain falls.

Charlotte Amalie sees seasonal dust haze (July), heaviest in July.

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

Is September a good time to visit Charlotte Amalie?

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

4.8
Sightseeing
12th-best month of the year
5.7
Beach & pool
12th-best month of the year

September is a reasonable time to visit Charlotte Amalie for sightseeing.

What to pack for Charlotte Amalie in September

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

In September, Charlotte Amalie sees daytime highs around 28°C and nights near 27°C. Pack light clothes and rain gear. Worth having: sun protection and a windbreaker. About 18 days see rain.

light clothesrain gearsun protectiona windbreaker

Sea temperature near Charlotte Amalie in September

The nearest coast averages about 29°C 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 September at about 29°C and coldest in February near 26°C.

The water stays above 20°C all year — warm enough for a swim any month.

24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan26Warm
Feb26Warm
Mar26Warm
Apr27Warm
May27Warm
Jun28Tropical
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov28Tropical
Dec27Warm

UV index in Charlotte Amalie in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Charlotte Amalie peaks around April 13 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 7 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highApr 13UV 13Dec 17UV 7
UV index (midday)Level
Jan8Very high
Feb10Extreme
Mar12Extreme
Apr13Extreme
May11Extreme
Jun12Extreme
Jul12Extreme
Aug11Extreme
Sep12Extreme
Oct10Very high
Nov8Very high
Dec7High

Air quality in Charlotte Amalie 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 Charlotte Amalie is worst in July — around 24 µg/m³ PM2.5 (moderate), about 4.5× the cleanest month (January, 5 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1124 µg/m³Jan 15 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb7Good
Mar7Good
Apr9Good
May14Moderate
Jun24Moderate
Jul24Moderate
Aug20Moderate
Sep15Moderate
Oct15Moderate
Nov8Good
Dec5Good
Location & terrain

Where is Charlotte Amalie?

Charlotte Amalie sits at 18.3°N, 64.9°W, 6 m above sea level, in U.S. Virgin Islands. The nearest listed city is Road Town, 34 km away.

Road TownSaint Croix

Topography around Charlotte Amalie

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Charlotte Amalie.

Within 3 km, the terrain around Charlotte Amalie has significant variations in elevation — a maximum elevation change of 454 m around an average of 89 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 471 m; within 80 km, significant variations in elevation — a maximum elevation change of 515 m.

The land around Charlotte Amalie is covered by trees (52%) and water (29%) within 3 km, water (90%) within 16 km, and water (95%) within 80 km.

3 km
454 m
16 km
471 m
80 km
515 m
treesgrasslandartificial surfaceswater
September weather nearby: Road Town 34 km · Saint Croix 71 km · Fajardo 76 km · Humacao 97 km · Carolina 108 km · Trujillo Alto 114 km · Caguas 119 km · Guaynabo 125 km

U.S. Virgin Islands travel facts

Power plugs
Type A / B
110 V · 60 Hz
Prices
≈ 89% of US
price level, 2022
GDP per capita
$44,321
2022
Safe drinking water
99%
of population, 2024
Homicide rate
49.9
per 100k, 2012
Income group
High
World Bank

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 Charlotte Amalie (18.3419°, -64.9307°, elevation 6 m), 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).