Gili Trawangan weather in September

In September, Gili Trawangan sees average daytime highs of 27°C and overnight lows near 25°C, with 13 mm of rain across 3.1 wet days and about 12 hours of daylight. It is the 8th-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 59% of the time in September, and the air most often feels oppressive.

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 Gili Trawangan's 2nd-clearest and 1st-windiest month. For the whole year in context, see Gili Trawangan's year-round climate.

Daytime high
27°
8th warmest
Overnight low
25°
3rd coldest
Rainfall
13 mm
3.1 wet days
Daylight
12 hours
6:12 AM – 6:09 PM
Cloud cover
37%
2nd clearest
Wind
17 km/h
1st windiest
Solar energy
6.84 kWh/m²
Travel score
7.8
out of 10

Gili Trawangan is town.

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 27°C through the month.

A typical September day in Gili Trawangan reaches about 27°C in the afternoon and slips back to 25°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 28°C. Set against its neighbours, September runs on par with August and on par with October.

20°23°25°28°30°151015202530
Avg high (°C)Avg low (°C)
12725
22725
32725
42725
52725
62725
72725
82725
92725
102725
112725
122725
132725
142725
152725
162725
172725
182726
192726
202726
212726
222726
232726
242726
252726
262726
272726
282726
292726
302826

How September really feels in Gili Trawangan

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.

Gili Trawangan weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 26°25726.312.43.8
Feb27° / 26°23225.112.33.7
Mar28° / 26°19524.712.14.2
Apr28° / 27°11319.811.84.7
May28° / 27°4411.411.66.0
Jun28° / 26°317.511.57.0
Jul27° / 25°225.511.67.5
Aug27° / 25°103.511.77.9
Sep27° / 25°133.1127.8
Oct28° / 26°338.212.26.8
Nov28° / 27°10518.112.44.9
Dec28° / 26°23225.412.54.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 59% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 24%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18020
28020
38020
48020
58020
67921
77921
87921
97921
107921
117822
127822
137822
147822
157822
167723
177624
187624
197624
207426
217426
227426
237426
247327
257228
267228
277129
287129
297030
307030

Chance of precipitation in September

Any precipitation

Gili Trawangan gets around 13 mm of rain over 3.1 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 11% and peaks near 14% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%151015202530
Rain chance (%)
17
27
37
47
57
68
78
88
99
109
1110
1210
1311
1412
1512
1613
1713
1813
1914
2014
2114
2214
2314
2414
2514
2614
2714
2814
2914
3014

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 87% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
119801
219801
318811
417821
516831
616831
715850
814860
913870
1013861
1112871
1211881
1311881
1410891
159901
169892
178902
188902
197912
207903
216913
226904
236904
245914
255905
265896
275896
285887
294897
304888

Wind in September

Winds average 17 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 15 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
115light breeze
215light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1617light breeze
1717light breeze
1817light breeze
1917light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2718light breeze
2818light breeze
2918light breeze
3018light 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 6:20 AM to 6:03 AM, and sunset from 6:11 PM to 6:07 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.86:206:11
211.86:206:11
311.96:196:10
411.96:196:10
511.96:186:10
611.96:186:10
711.96:176:10
811.96:166:10
911.96:166:10
1011.96:156:10
1111.96:156:09
1211.96:146:09
1311.96:136:09
1411.96:136:09
1511.96:126:09
1612.06:126:09
1712.06:116:09
1812.06:106:09
1912.06:106:08
2012.06:096:08
2112.06:086:08
2212.06:086:08
2312.06:076:08
2412.06:076:08
2512.06:066:08
2612.06:066:08
2712.06:056:07
2812.06:046:07
2912.16:046:07
3012.16:036:07

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.84 kWh/m².

For context, solar energy here swings from a low near 5.32 kWh/m² to a high of 7.03 kWh/m² in October across the year — September's 6.84 kWh/m² sits near the top of that range.

02468151015202530
Solar energy (kWh/m²)Level
16.6Intense
26.6Intense
36.6Intense
46.6Intense
56.7Intense
66.7Intense
76.7Intense
86.7Intense
96.7Intense
106.8Intense
116.8Intense
126.8Intense
136.8Intense
146.8Intense
156.8Intense
166.8Intense
176.9Intense
186.9Intense
196.9Intense
206.9Intense
216.9Intense
226.9Intense
236.9Intense
247.0Intense
257.0Intense
267.0Intense
277.0Intense
287.0Intense
297.0Intense
307.0Intense
Planning a trip in September

Hazard calendar for Gili Trawangan

In seasonPeak

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

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

Gili Trawangan's monsoon runs December–March, when most of the year's rain falls.

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

Is September a good time to visit Gili Trawangan?

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

7.8
Sightseeing
2nd-best month of the year
8.0
Beach & pool
1st-best month of the year

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

What to pack for Gili Trawangan in September

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

In September, Gili Trawangan sees daytime highs around 27°C and nights near 25°C. Pack light clothes and sun protection. About 3 days see rain.

light clothessun protection

Sea temperature near Gili Trawangan in September

The nearest coast averages about 28°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 April at about 29°C and coldest in August near 28°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
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr29Tropical
May29Tropical
Jun29Tropical
Jul28Warm
Aug28Warm
Sep28Warm
Oct29Tropical
Nov29Tropical
Dec29Tropical

UV index in Gili Trawangan in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Gili Trawangan peaks around March 12 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 18 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 highExtremeMar 12UV 14Jun 18UV 9
UV index (midday)Level
Jan13Extreme
Feb14Extreme
Mar14Extreme
Apr13Extreme
May10Extreme
Jun9Very high
Jul10Very high
Aug12Extreme
Sep13Extreme
Oct12Extreme
Nov11Extreme
Dec13Extreme

Air quality in Gili Trawangan 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 Gili Trawangan is worst in October — around 22 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (April, 13 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateOct 2022 µg/m³Apr 1613 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb14Moderate
Mar14Moderate
Apr13Moderate
May14Moderate
Jun14Moderate
Jul13Moderate
Aug14Moderate
Sep18Moderate
Oct22Moderate
Nov21Moderate
Dec15Moderate
Location & terrain

Where is Gili Trawangan?

Gili Trawangan sits at 8.3°S, 116.0°E, 0 m above sea level, in Indonesia. The nearest listed city is Lombok, 27 km away.

Topography around Gili Trawangan

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

Within 3 km, the terrain around Gili Trawangan has only modest variations in elevation — a maximum elevation change of 75 m around an average of 1 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 853 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,635 m.

The land around Gili Trawangan is covered by water (84%) within 3 km, water (81%) within 16 km, and water (63%) and trees (27%) within 80 km.

3 km
75 m
16 km
853 m
80 km
3,635 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Lombok 27 km · Praya 47 km · Amlapura 48 km · Amlapura city 49 km · Bedugul 50 km · Selong 64 km · Klungkung 73 km · Ubud 87 km

Indonesia travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 29% of US
price level, 2025
GDP per capita
$5,060
2025
Happiness
5.6 / 10
World Happiness, 2025
Safe drinking water
30%
of population, 2024
Homicide rate
0.3
per 100k, 2022
Road deaths
11.3
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 471
Religion
Muslim 87%Protestant 8%Roman Catholic 3%Hindu 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 Gili Trawangan (-8.349°, 116.037°, elevation 0 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).