Koh Rong in May
Last fact-checked: October 2026. Climate figures are long-term averages for nearby Sihanoukville.
May is a transition month: hot at first, with the rainy season usually starting around the middle of the month.
| Average daytime high | 33 °C |
| Average night-time low | 25 °C |
| Average rainfall | 293 mm |
| Average sea temperature | 30.3 °C |
Long-term averages for nearby Sihanoukville: World Meteorological Organization 1982-2024; sea temperature: seatemperature.org.
Weather
Days are hot, at about 33°C on average, and showers become more frequent, often as short, heavy downpours in the afternoon or at night.
Sea and activities
The sea is at its warmest, around 30°C. It is still often calm in the first half of the month.
Holidays and crowds
The low season begins and many resorts start offering discounts. The island becomes noticeably quieter.
Best Beaches & Coast Conditions in May
Early May is calm across the entire island; by late May, as southwest breezes pick up, the east coast (Long Set, Pagoda, Coconut Beach) becomes noticeably calmer than the west coast.
- Recommended Activities: Warmest ocean water of the year (30.3 °C), great morning snorkeling, strong bioluminescent plankton glow at night, and the first flow of water in the jungle waterfalls.
- What to Pack & Booking Tip: Light quick-dry clothing, a compact rain poncho, a waterproof dry bag for phones and cameras on boats, and coconut oil for sandflies.
Koh Rong Weather in May: FAQ
Is May a good month to visit Koh Rong?
May is an excellent value shoulder month: the first half of May still feels like dry season, hotel rates drop by 20–30%, and showers usually fall in short late-afternoon bursts.
Which side of Koh Rong is best to stay on in May?
Long Set (4K Beach), Pagoda Beach, and Coconut Beach on the sheltered east/south-east coast offer the calmest swimming as the southwest monsoon begins in late May.
Are waterfalls flowing on Koh Rong in May?
By mid-to-late May, regular tropical showers bring Varisan Nureach Waterfall near Sok San back to life.