Roseau weather in September

In September, Roseau sees average daytime highs of 28°C and overnight lows near 26°C, with 113 mm of rain across 17.1 wet days and about 12.1 hours of daylight. It is the 1st-warmest and 2nd-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 36% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 18 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Roseau's 12th-clearest and 12th-windiest month. For the whole year in context, see Roseau's year-round climate.

Daytime high
28°
1st warmest
Overnight low
26°
12th coldest
Rainfall
113 mm
17.1 wet days
Daylight
12 h 06 min
5:57 AM – 6:02 PM
Cloud cover
59%
12th clearest
Wind
22 km/h
12th windiest
Solar energy
6.01 kWh/m²
Travel score
5.3
out of 10

Roseau is capital of Dominica.

Density
3,069/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

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

A typical September day in Roseau reaches about 28°C in the afternoon and slips back to 26°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 28°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)
12826
22826
32826
42826
52826
62826
72826
82826
92826
102826
112826
122826
132826
142826
152826
162826
172826
182826
192826
202826
212826
222826
232826
242826
252826
262826
272826
282826
292826
302826

Roseau weather by month

How September compares with the rest of the year at a glance. September is the 1st-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan26° / 24°321211.27.1
Feb25° / 24°19711.57.8
Mar25° / 24°196.911.97.8
Apr26° / 25°298.312.37.2
May27° / 25°4410.212.76.7
Jun27° / 26°4710.512.96.4
Jul27° / 26°7616.412.85.8
Aug28° / 26°9918.412.55.4
Sep28° / 26°11317.112.15.3
Oct28° / 26°11819.111.75.2
Nov27° / 26°10117.111.35.7
Dec26° / 25°4814.211.16.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 49%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15842
25842
35842
45743
55743
65644
75545
85446
95446
105347
115248
125149
135050
144951
154951
164852
174753
184753
194753
204654
214753
224654
234654
244753
254753
264753
274753
284753
294753
304753

Chance of precipitation in September

Any precipitation

Roseau gets around 113 mm of rain over 17.1 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 58% and peaks near 63% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
153
253
353
453
554
654
754
855
956
1056
1156
1257
1357
1458
1558
1658
1759
1859
1959
2059
2159
2259
2359
2460
2560
2661
2761
2862
2963
3063

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 72% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
17030
27030
37030
46931
56931
66931
76931
86931
96931
107030
117030
127030
137030
147129
157129
167228
177228
187327
197426
207426
217525
227525
237525
247624
257624
267624
277624
287624
297624
307624

Wind in September

Winds average 22 km/h in September, the calmest month.

Across September, daily wind ranges from about 22 km/h on the calmest days to 23 km/h at its breeziest. It stays fairly steady from day to day.

0102030151015202530
Wind speed (km/h)Feels
123breezy
223breezy
323breezy
423breezy
523breezy
623breezy
723breezy
823breezy
923breezy
1023breezy
1123breezy
1223breezy
1323breezy
1423breezy
1523breezy
1623breezy
1722breezy
1822breezy
1922breezy
2022breezy
2122breezy
2222breezy
2322breezy
2422breezy
2522breezy
2622breezy
2722breezy
2822breezy
2922breezy
3022breezy

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 18 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 24 minutes over September. Sunrise moves from 5:56 AM to 5:58 AM, and sunset from 6:14 PM to 5:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.35:566:14
212.35:566:14
312.35:566:13
412.35:566:12
512.25:576:11
612.25:576:10
712.25:576:10
812.25:576:09
912.25:576:08
1012.25:576:07
1112.25:576:06
1212.15:576:06
1312.15:576:05
1412.15:576:04
1512.15:576:03
1612.15:576:02
1712.15:576:02
1812.15:576:01
1912.05:586:00
2012.05:585:59
2112.05:585:58
2212.05:585:58
2312.05:585:57
2412.05:585:56
2512.05:585:55
2611.95:585:54
2711.95:585:54
2811.95:585:53
2911.95:585:52
3011.95:585:51

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.01 kWh/m².

For context, solar energy here swings from a low near 4.81 kWh/m² to a high of 6.7 kWh/m² in April across the year — September's 6.01 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.2Intense
26.2Intense
36.2Intense
46.2Intense
56.2Intense
66.2Intense
76.2Intense
86.1Intense
96.1Intense
106.1Intense
116.1Intense
126.1Intense
136.0Intense
146.0Intense
156.0Intense
166.0Intense
176.0Bright
186.0Bright
195.9Bright
205.9Bright
215.9Bright
225.9Bright
235.9Bright
245.9Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
Planning a trip in September

Hazard calendar for Roseau

In seasonPeak

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

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

Roseau's rainy season runs July–November, when most of the year's rain falls.

Roseau sees seasonal dust haze (June–July), heaviest in June.

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

Is September a good time to visit Roseau?

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

5.3
Sightseeing
11th-best month of the year
5.6
Beach & pool
11th-best month of the year

September is a reasonable time to visit Roseau for sightseeing.

What to pack for Roseau in September

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

In September, Roseau sees daytime highs around 28°C and nights near 26°C. Pack light clothes, rain gear and sun protection. Worth having: a windbreaker. About 17 days see rain.

light clothesrain gearsun protectiona windbreaker

Sea temperature near Roseau 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 27°C.

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

26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb27Warm
Mar27Warm
Apr27Warm
May28Warm
Jun28Warm
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index in Roseau 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 Roseau peaks around March 21 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highMar 21UV 13Dec 13UV 8
UV index (midday)Level
Jan9Very high
Feb11Extreme
Mar14Extreme
Apr13Extreme
May12Extreme
Jun11Extreme
Jul12Extreme
Aug11Extreme
Sep12Extreme
Oct11Extreme
Nov8Very high
Dec8Very high

Air quality in Roseau 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 Roseau is worst in June — around 28 µg/m³ PM2.5 (moderate), about 3.1× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodJun 2028 µg/m³Dec 239 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar11Good
Apr15Moderate
May18Moderate
Jun28Moderate
Jul26Moderate
Aug21Moderate
Sep16Moderate
Oct18Moderate
Nov12Moderate
Dec9Good
Location & terrain

Where is Roseau?

Roseau sits at 15.3°N, 61.4°W, 11 m above sea level, in Dominica. The nearest listed city is Sainte-Marie, 72 km away.

Topography around Roseau

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

Within 3 km, the terrain around Roseau has significant variations in elevation — a maximum elevation change of 417 m around an average of 66 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,383 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,389 m.

The land around Roseau is covered by water (55%) and trees (38%) within 3 km, water (58%) and trees (41%) within 16 km, and water (89%) within 80 km.

3 km
417 m
16 km
1,383 m
80 km
1,389 m
treesartificial surfaceswater
September weather nearby: Sainte-Marie 72 km · La Trinité 78 km · Saint-Joseph 80 km · Le Robert 84 km · Fort-de-France 85 km · Capesterre-Belle-Eau 85 km · Basse-Terre 86 km · Le Lamentin 87 km

Dominica travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type D / G
230 V · 50 Hz
Prices
≈ 48% of US
price level, 2025
GDP per capita
$10,989
2025
Homicide rate
27.1
per 100k, 2023
Road deaths
10.9
per 100k/yr, 2016
Income group
Upper middle
World Bank
Religion
Roman Catholic 53%Protestant 30%none 9%other 4%

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 Roseau (15.3017°, -61.3881°, elevation 11 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).