Koh Kong weather in September

In September, Koh Kong sees average daytime highs of 28°C and overnight lows near 25°C, with 520 mm of rain across 29.3 wet days and about 12.1 hours of daylight. It is the 11th-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 1% 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 Koh Kong's 12th-clearest and 4th-windiest month. For the whole year in context, see Koh Kong's year-round climate.

Daytime high
28°
11th warmest
Overnight low
25°
7th coldest
Rainfall
520 mm
29.3 wet days
Daylight
12 h 06 min
6:00 AM – 6:04 PM
Cloud cover
91%
12th clearest
Wind
10 km/h
4th windiest
Solar energy
4.01 kWh/m²
Travel score
3.2
out of 10

Koh Kong is capital in the eponymous province of Cambodia.

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 Koh Kong reaches about 28°C in the afternoon and slips back to 25°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 29°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)
12825
22825
32825
42825
52825
62825
72825
82825
92825
102825
112825
122825
132825
142825
152825
162825
172825
182825
192825
202825
212825
222825
232825
242825
252825
262825
272825
282825
292825
302825

How September really feels in Koh Kong

Once humidity and wind are folded in, September averages 10 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
10
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.

Koh Kong weather by month

How September compares with the rest of the year at a glance. September is the 11th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 23°40811.45.6
Feb29° / 24°4610.111.65.4
Mar30° / 25°10418.411.94.3
Apr30° / 25°14423.112.33.4
May29° / 26°3632912.52.9
Jun29° / 25°51528.912.73.0
Jul28° / 25°61430.112.63.2
Aug28° / 25°59630.312.43.2
Sep28° / 25°52029.312.13.2
Oct29° / 25°31026.711.73.4
Nov30° / 25°8213.911.54.5
Dec30° / 24°316.711.35.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 1% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 3% of September, with mostly cloudy or overcast conditions the remaining 96%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1397
2397
3397
4397
5298
6298
7298
8298
9298
10298
11397
12397
13397
14496
15496
16496
17496
18496
19595
20694
21694
22694
23694
24694
25595
26595
27595
28496
29496
30595

Chance of precipitation in September

Any precipitation

Koh Kong gets around 520 mm of rain over 29.3 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 98% and peaks near 98% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
197
298
398
498
598
698
798
898
998
1098
1198
1298
1398
1498
1598
1698
1798
1898
1998
2098
2197
2297
2397
2497
2597
2697
2797
2897
2997
3097

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 52% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
13565
23664
33763
43961
54060
64258
74357
84456
94555
104654
114753
124852
134951
145050
155050
165149
175149
185248
195248
205248
215248
225248
235248
245347
255347
265446
275545
285644
295743
305842

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
112calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
249calm
259calm
269calm
279calm
289calm
299calm
308calm

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 6:01 AM to 6:00 AM, and sunset from 6:15 PM to 5:55 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.26:016:15
212.26:016:14
312.26:016:13
412.26:016:13
512.26:016:12
612.26:016:11
712.26:016:11
812.26:016:10
912.16:016:09
1012.16:016:08
1112.16:016:08
1212.16:016:07
1312.16:016:06
1412.16:016:06
1512.16:016:05
1612.16:006:04
1712.16:006:04
1812.06:006:03
1912.06:006:02
2012.06:006:01
2112.06:006:01
2212.06:006:00
2312.06:005:59
2412.06:005:59
2512.06:005:58
2612.06:005:57
2711.96:005:57
2811.96:005:56
2911.96:005:55
3011.96:005:55

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.01 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 4.01 kWh/m² to a high of 5.9 kWh/m² in April across the year — September's 4.01 kWh/m² sits near the bottom.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.2Bright
34.1Bright
44.1Bright
54.1Bright
64.1Bright
74.1Bright
84.0Bright
94.0Bright
104.0Bright
114.0Moderate
124.0Moderate
133.9Moderate
143.9Moderate
153.9Moderate
163.9Moderate
173.9Moderate
183.9Moderate
193.9Moderate
203.9Moderate
213.9Moderate
224.0Moderate
234.0Moderate
244.0Moderate
254.0Bright
264.0Bright
274.0Bright
284.1Bright
294.1Bright
304.1Bright
Planning a trip in September

Hazard calendar for Koh Kong

In seasonPeak

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

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

Koh Kong'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 Koh Kong?

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

3.2
Sightseeing
8th-best month of the year
3.5
Beach & pool
11th-best month of the year

September is a weaker month for outdoor sightseeing in Koh Kong.

What to pack for Koh Kong in September

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

In September, Koh Kong sees daytime highs around 28°C and nights near 25°C. Pack light clothes and rain gear. About 29 days see rain.

light clothesrain gear

Sea temperature near Koh Kong 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
Feb29Tropical
Mar29Tropical
Apr30Tropical
May31Tropical
Jun30Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec29Tropical

UV index in Koh Kong 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 Koh Kong peaks around August 18 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 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 14Dec 13UV 9
UV index (midday)Level
Jan10Very high
Feb11Extreme
Mar13Extreme
Apr12Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug14Extreme
Sep13Extreme
Oct11Extreme
Nov9Very high
Dec9Very high

Air quality in Koh Kong 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 Koh Kong is worst in February — around 24 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (November, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodFeb 1523 µg/m³Nov 129 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb24Moderate
Mar19Moderate
Apr16Moderate
May12Moderate
Jun12Good
Jul14Moderate
Aug12Good
Sep10Good
Oct10Good
Nov9Good
Dec11Good
Location & terrain

Where is Koh Kong?

Koh Kong sits at 11.6°N, 103.0°E, 5 m above sea level, in Cambodia. The nearest listed city is Smach Mean Chey, 10 km away.

TratKo ChangLaem NgopKhao SamingSihanoukvilleLaem Sing

Topography around Koh Kong

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

Within 3 km, the terrain around Koh Kong has only modest variations in elevation — a maximum elevation change of 20 m around an average of 3 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 488 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,727 m.

The land around Koh Kong is covered by water (36%) and grassland (28%) within 3 km, water (40%) and trees (39%) within 16 km, and trees (51%) and water (43%) within 80 km.

3 km
20 m
16 km
488 m
80 km
1,727 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetlandmangroves
September weather nearby: Smach Mean Chey 10 km · Khlong Yai 21 km · Trat 86 km · Ko Chang 88 km · Laem Ngop 89 km · Khao Saming 102 km · Sihanoukville 127 km · Laem Sing 138 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 Koh Kong (11.6153°, 102.9838°, elevation 5 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).