Fomboni weather in September

In September, Fomboni sees average daytime highs of 25°C and overnight lows near 24°C, with 7 mm of rain across 2.2 wet days and about 11.9 hours of daylight. It is the 11th-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 25°C through the month. The sky is clear or mostly clear about 85% of the time in September, and the air most often feels muggy.

Daylight stretches from about 11 h 48 min at the start of September to 12 h 06 min by month's end. Set against the rest of the year, September is Fomboni's 1st-clearest and 9th-windiest month. For the whole year in context, see Fomboni's year-round climate.

Daytime high
25°
11th warmest
Overnight low
24°
2nd coldest
Rainfall
7 mm
2.2 wet days
Daylight
11 h 54 min
6:01 AM – 5:57 PM
Cloud cover
24%
1st clearest
Wind
13 km/h
9th windiest
Solar energy
6.24 kWh/m²
Travel score
8.8
out of 10

Fomboni is Capital of Mohéli.

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 25°C through the month.

A typical September day in Fomboni reaches about 25°C in the afternoon and slips back to 24°C overnight — a 1°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 26°C. Set against its neighbours, September runs on par with August and about 1°C cooler than October.

20°23°25°28°30°151015202530
Avg high (°C)Avg low (°C)
12524
22524
32524
42524
52524
62524
72524
82524
92524
102524
112524
122524
132524
142524
152524
162524
172524
182524
192524
202524
212524
222524
232524
242524
252524
262524
272525
282525
292525
302625

How September really feels in Fomboni

Once humidity and wind are folded in, September averages 0 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
0
heat index over the day's high
Days feeling ≤ C
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.

Fomboni weather by month

How September compares with the rest of the year at a glance. September is the 11th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 27°16817.612.65.1
Feb28° / 27°15916.912.44.8
Mar28° / 27°13919.512.14.7
Apr28° / 27°8814.111.75.8
May27° / 26°316.911.47.4
Jun26° / 25°174.111.38.1
Jul25° / 24°133.311.48.5
Aug25° / 24°82.411.68.8
Sep25° / 24°72.211.98.8
Oct26° / 25°133.212.38.4
Nov27° / 26°314.912.67.8
Dec28° / 26°841312.76.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 85% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 10% of September, with mostly cloudy or overcast conditions the remaining 5%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1964
2964
3964
4964
5964
6964
7955
8955
9955
10955
11955
12955
13955
14955
15955
16955
17955
18964
19964
20964
21964
22964
23955
24955
25955
26955
27955
28955
29955
30946

Chance of precipitation in September

Any precipitation

Fomboni gets around 7 mm of rain over 2.2 wet days in September, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 7% and peaks near 9% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
17
27
36
46
56
66
76
86
97
107
117
127
137
147
158
168
178
188
198
208
218
228
238
248
258
268
278
288
299
309

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 72% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202530
Humid (%)Muggy (%)Oppressive (%)
128711
238512
338512
438413
528513
628414
728315
828315
928216
1028117
1128117
1218118
1317920
1417821
1517623
1617425
1717227
1817029
1907030
2006832
2106634
2206535
2306337
2406139
2505941
2605842
2705644
2805446
2905347
3005149

Wind in September

Winds average 13 km/h in September.

Across September, daily wind ranges from about 12 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 48 min at the start of September to 12 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 18 minutes over September. Sunrise moves from 6:12 AM to 5:51 AM, and sunset from 5:58 PM to 5:57 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.86:125:58
211.86:115:58
311.86:115:58
411.86:105:58
511.86:095:58
611.86:095:58
711.86:085:58
811.86:075:57
911.96:065:57
1011.96:065:57
1111.96:055:57
1211.96:045:57
1311.96:045:57
1411.96:035:57
1511.96:025:57
1611.96:015:57
1711.96:015:57
1812.06:005:57
1912.05:595:57
2012.05:585:57
2112.05:585:57
2212.05:575:57
2312.05:565:57
2412.05:565:57
2512.05:555:57
2612.05:545:57
2712.15:545:57
2812.15:535:57
2912.15:525:57
3012.15:515:57

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.24 kWh/m².

For context, solar energy here swings from a low near 4.72 kWh/m² to a high of 6.95 kWh/m² in November across the year — September's 6.24 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.9Bright
26.0Bright
36.0Bright
46.0Intense
56.0Intense
66.0Intense
76.1Intense
86.1Intense
96.1Intense
106.1Intense
116.2Intense
126.2Intense
136.2Intense
146.2Intense
156.2Intense
166.3Intense
176.3Intense
186.3Intense
196.3Intense
206.3Intense
216.4Intense
226.4Intense
236.4Intense
246.4Intense
256.4Intense
266.5Intense
276.5Intense
286.5Intense
296.5Intense
306.5Intense
Planning a trip in September

Hazard calendar for Fomboni

In seasonPeak

None of Fomboni's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Fomboni sits in the South Indian Ocean cyclone belt; the season peaks January–March.

Fomboni's rainy season runs December–April, when most of the year's rain falls.

Cyclone
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Fomboni?

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

8.8
Sightseeing
1st-best month of the year
8.0
Beach & pool
2nd-best month of the year

September is one of the better times to visit Fomboni for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Fomboni in September

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

In September, Fomboni sees daytime highs around 25°C and nights near 24°C. Pack sun protection. Worth having: light clothes.

sun protectionlight clothes

Sea temperature near Fomboni in September

The nearest coast averages about 26°C 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 16 km away) is warmest in March at about 30°C and coldest in August 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
Jan29Tropical
Feb29Tropical
Mar30Tropical
Apr29Tropical
May28Tropical
Jun27Warm
Jul26Warm
Aug26Warm
Sep26Warm
Oct27Warm
Nov28Warm
Dec29Tropical

UV index in Fomboni 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 Fomboni peaks around February 15 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 20 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeFeb 15UV 15Jun 20UV 9
UV index (midday)Level
Jan14Extreme
Feb15Extreme
Mar14Extreme
Apr12Extreme
May10Very high
Jun9Very high
Jul9Very high
Aug11Extreme
Sep12Extreme
Oct13Extreme
Nov12Extreme
Dec13Extreme
Location & terrain

Where is Fomboni?

Fomboni sits at 12.3°S, 43.7°E, 18 m above sea level, in Comoros. The nearest listed city is Moutsamoudou, 73 km away.

MoutsamoudouMoroni

Topography around Fomboni

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

Within 3 km, the terrain around Fomboni has significant variations in elevation — a maximum elevation change of 554 m around an average of 100 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 780 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,346 m.

The land around Fomboni is covered by trees (52%) and water (39%) within 3 km, water (75%) and trees (24%) within 16 km, and water (92%) within 80 km.

3 km
554 m
16 km
780 m
80 km
2,346 m
treesgrasslandartificial surfaceswater
September weather nearby: Moutsamoudou 73 km · Moroni 84 km · Koungou 166 km · Mtsapéré 169 km · Kaouéni 169 km · Mamoudzou 170 km · Dzaoudzi 173 km · Labattoir 176 km

Comoros travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
220 V · 50 Hz
Prices
≈ 49% of US
price level, 2025
GDP per capita
$2,056
2025
Happiness
3.9 / 10
World Happiness, 2025
Road deaths
26.6
per 100k/yr, 2019
Income group
Lower middle
World Bank
Religion
Muslim 98%ethnic religionist 1%Christian 1%other 0%

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 Fomboni (-12.2876°, 43.7434°, elevation 18 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).