SeasonMapKoh Rong weather in September
Cambodia
September in Koh Rong: hot, soaked, with clean air — a gamble, with 29 rainy days.
#12 of 12 months in Koh Rong · #1251 of 1383 destinations to visit in September · comfort 51/100 (tier D)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Koh Rong in September
No notes yet. Open Koh Rong on the map to add the first one.
Koh Rong climate normals — September
| Daytime high | 29°C / 85°F | 🥵 hot |
|---|---|---|
| Nighttime low | 26°C / 78°F | |
| Sea temperature | 29°C / 85°F | ♨️ bath-warm |
| Rainfall | 579 mm / 22.8 in | ⛈ soaked |
| Rainy days | 29 days | |
| Humidity | 89% | 💦 very humid |
| Dew point | 25°C / 77°F | |
| Sunshine | 6.8 h/day | |
| Daylight | 12.2 h | |
| Wind | 17 km/h / 10 mph | |
| Air quality (US AQI) | 37 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Koh Rong in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Quietschool holidays in 3 of the markets that fill it, one of its worst months for weather(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Koh Rong's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Toughest weatherKoh Rong's weather peaks December–February.
Best weatherFair weatherToughest weather
What's on in Koh Rong in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Rough crossings in the wet
1 Jun – 15 Oct · usuallyMonsoonRiskThe southwest monsoon puts a swell across the channel and the fast boats from Sihanoukville get cancelled at short notice. Leave a spare day either side of a flight.
- Season
Wet season
MonsoonRisk29 rainy days and about 579 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
Nearby, and something's on
Within 300 km of Koh Rong — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Koh Rong?
Koh Rong in September — FAQ
- Is September a good time to visit Koh Rong?
- September in Koh Rong: hot, soaked, with clean air — a gamble, with 29 rainy days. It ranks #12 of 12 months for Koh Rong on SeasonMap's comfort score (51/100).
- What is the weather like in Koh Rong in September?
- In September, Koh Rong averages a daily high of 29.2°C and a low of 25.8°C, with about 579.3 mm of rain over roughly 29 rainy days.
- What is the air quality in Koh Rong in September?
- Koh Rong has a mean US Air Quality Index of about 37 in September.
Other months in Koh Rong
Compare Koh Rong in September
Warmer or cooler than Koh Rong in September
Similar destinations in Southeast Asia — September
Within 300 km: Phnom Penh's Pchum Ben around 10 Sep – 10 Oct, and Phu Quoc's Phu Quoc visa exemption on 1 Jan – 31 Dec.