Tonle Sap Cambodia SS sAs the rainy season reaches its peak the temperatures continue to be very comfortable (mid-20s°C) and away from the coast, the showers tend to be afternoon thunderstorms rather than a total washout. When in Siem Reap make sure you include a day tour to the stilted villages of Tonle Sap Lake (largest in SE Asia), as the rains have replenished it and the fauna and flora are in full bloom making this a good time to visit for wildlife (bird) enthusiasts and photographers.