Sihanoukville weather in September

In September, Sihanoukville sees average daytime highs of 28°C and overnight lows near 26°C, with 554 mm of rain across 28.4 wet days and about 12.1 hours of daylight. It is the 12th-warmest and 3rd-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 3% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 h 12 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Sihanoukville's 12th-clearest and 3rd-windiest month. For the whole year in context, see Sihanoukville's year-round climate.

Daytime high
28°
12th warmest
Overnight low
26°
5th coldest
Rainfall
554 mm
28.4 wet days
Daylight
12 h 06 min
5:58 AM – 6:02 PM
Cloud cover
88%
12th clearest
Wind
17 km/h
3rd windiest
Solar energy
4.56 kWh/m²
Travel score
3.4
out of 10

Sihanoukville is city in Preah Sihanouk Province, Cambodia.

Density
913/km²
people per km²
Founded
1964

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 Sihanoukville 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 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)
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

How September really feels in Sihanoukville

Once humidity and wind are folded in, September averages 22 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
22
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.

Sihanoukville weather by month

How September compares with the rest of the year at a glance. September is the 12th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 26°379.811.46.4
Feb28° / 26°308.211.66.3
Mar29° / 26°6513.511.95.3
Apr29° / 27°1151912.24.2
May29° / 27°37827.912.53.1
Jun29° / 27°48927.712.63.1
Jul28° / 26°55829.412.63.1
Aug28° / 26°55628.912.33.3
Sep28° / 26°55428.412.13.4
Oct28° / 26°34327.111.83.6
Nov29° / 26°10415.411.54.8
Dec29° / 26°449.311.45.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 3% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 5% of September, with mostly cloudy or overcast conditions the remaining 93%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1793
2793
3793
4694
5694
6694
7694
8694
9694
10595
11694
12694
13694
14694
15694
16793
17892
18892
19892
20991
21991
22991
23991
24991
25991
26991
27991
28991
29892
30892

Chance of precipitation in September

Any precipitation

Sihanoukville gets around 554 mm of rain over 28.4 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 95% and peaks near 95% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
194
294
394
494
594
694
794
895
995
1095
1195
1295
1395
1495
1595
1695
1795
1895
1995
2095
2195
2295
2395
2495
2595
2695
2795
2895
2994
3094

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 70% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
12179
22179
32278
42377
52476
62476
72575
82674
92674
102773
112872
122872
132971
142971
152971
163070
173070
183070
193070
203169
213169
223268
233367
243466
253664
263763
273961
284159
294357
304555

Wind in September

Winds average 17 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
118light breeze
218light breeze
318light breeze
418light breeze
518light breeze
618light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1418light breeze
1518light breeze
1618light breeze
1718light breeze
1817light breeze
1917light breeze
2017light breeze
2117light breeze
2217light breeze
2316light breeze
2416light breeze
2516light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 12 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 18 minutes over September. Sunrise moves from 5:59 AM to 5:58 AM, and sunset from 6:12 PM to 5:53 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.25:596:12
212.25:596:11
312.25:596:11
412.25:596:10
512.25:596:09
612.25:596:09
712.15:596:08
812.15:596:07
912.15:596:07
1012.15:596:06
1112.15:596:05
1212.15:596:05
1312.15:596:04
1412.15:596:03
1512.15:596:03
1612.15:586:02
1712.05:586:01
1812.05:586:01
1912.05:586:00
2012.05:585:59
2112.05:585:59
2212.05:585:58
2312.05:585:57
2412.05:585:57
2512.05:585:56
2612.05:585:55
2711.95:585:55
2811.95:585:54
2911.95:585:53
3011.95:585:53

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.56 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 4.56 kWh/m² to a high of 6.26 kWh/m² in March across the year — September's 4.56 kWh/m² sits near the bottom.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.7Bright
44.7Bright
54.7Bright
64.7Bright
74.7Bright
84.6Bright
94.6Bright
104.6Bright
114.6Bright
124.5Bright
134.5Bright
144.5Bright
154.5Bright
164.5Bright
174.5Bright
184.5Bright
194.5Bright
204.5Bright
214.5Bright
224.5Bright
234.5Bright
244.5Bright
254.5Bright
264.5Bright
274.5Bright
284.5Bright
294.5Bright
304.5Bright
Planning a trip in September

Hazard calendar for Sihanoukville

In seasonPeak

In September, Sihanoukville sits inside its pacific typhoon and monsoon season. The full year is below, with each hazard's peak months called out.

Sihanoukville sits in the Pacific typhoon belt; the season peaks July–October.

Sihanoukville's monsoon runs May–October, when most of the year's rain falls.

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

Is September a good time to visit Sihanoukville?

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

3.4
Sightseeing
8th-best month of the year
3.6
Beach & pool
12th-best month of the year

September is a weaker month for outdoor sightseeing in Sihanoukville.

What to pack for Sihanoukville in September

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

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

light clothesrain gearsun protection

Sea temperature near Sihanoukville 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 May at about 31°C and coldest in January near 28°C.

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

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Tropical
Feb28Tropical
Mar29Tropical
Apr30Tropical
May31Tropical
Jun30Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec29Tropical

UV index in Sihanoukville 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 Sihanoukville peaks around August 18 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 12 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 highAug 18UV 13Dec 12UV 9
UV index (midday)Level
Jan10Extreme
Feb11Extreme
Mar12Extreme
Apr12Extreme
May11Extreme
Jun12Extreme
Jul12Extreme
Aug14Extreme
Sep13Extreme
Oct11Extreme
Nov9Very high
Dec9Very high

Air quality in Sihanoukville 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 Sihanoukville is worst in February — around 24 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (September, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateModerateGoodModerateFeb 1423 µg/m³Sep 2210 µg/m³
PM2.5 (µg/m³)Level
Jan20Moderate
Feb24Moderate
Mar19Moderate
Apr17Moderate
May12Moderate
Jun12Good
Jul14Moderate
Aug11Good
Sep10Good
Oct11Good
Nov12Good
Dec15Moderate
Location & terrain

Where is Sihanoukville?

Sihanoukville sits at 10.6°N, 103.5°E, 6 m above sea level, in Cambodia. The nearest listed city is Phu Quoc, 65 km away.

Phu QuocKampotHàm NinhKepHà TiênSmach Mean CheyKoh KongÂngk Tasaôm

Topography around Sihanoukville

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

Within 3 km, the terrain around Sihanoukville has only modest variations in elevation — a maximum elevation change of 124 m around an average of 21 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 288 m; within 80 km, large variations in elevation — a maximum elevation change of 1,064 m.

The land around Sihanoukville is covered by artificial surfaces (36%) and water (28%) within 3 km, water (62%) and trees (20%) within 16 km, and water (63%) and trees (26%) within 80 km.

3 km
124 m
16 km
288 m
80 km
1,064 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
September weather nearby: Phu Quoc 65 km · Kampot 71 km · Hàm Ninh 74 km · Kep 87 km · Hà Tiên 108 km · Smach Mean Chey 117 km · Koh Kong 127 km · Ângk Tasaôm 133 km

Cambodia travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / C / G
230 V · 50 Hz
Prices
≈ 34% of US
price level, 2025
GDP per capita
$2,872
2025
Happiness
4.5 / 10
World Happiness, 2025
Safe drinking water
30%
of population, 2024
Homicide rate
1.8
per 100k, 2011
Road deaths
19.6
per 100k/yr, 2019
Income group
Lower middle
World Bank
English
Very low
EF EPI 390
Religion
Buddhist 97%Muslim 2%other 1%Christian 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 Sihanoukville (10.6093°, 103.5296°, 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).