Cambodia in September: Weather, Crowds & What to Expect

Siem Reap & Northwest (Angkor, Battambang)

Rain tapers off through October, but the countryside remains lush and rivers run high; mornings are often misty with temperatures easing back into the high 20s. The Water Festival (Bon Om Touk) usually falls in November but preparations and local boat practices are visible in the waterways now. This is a transitional month where crowds begin to pick up and outdoor night markets reappear.

Tonle Sap & Central Plains (Phnom Penh, Tonle Sap Lake, Kampong Thom)

September tends to be the height of the flood season on the Tonle Sap, with water levels at or near their annual maximum and many villages accessible only by boat. Road access to lakeside communities is limited, but the flooded forest habitat is fantastic for spotting shorebirds and storks. Travelers should expect erratic transport options and plan extra time for boat transfers; rainproof gear is essential and accommodation choices near the shore can be sparse.

Southern Coast & Islands (Sihanoukville, Koh Rong, Koh Rong Samloem, Kep)

September can be the wettest month on the southern coast, with heavy, sustained rainfall and high winds that make sea travel inadvisable at times. Resorts often operate at reduced capacity and some island activities, like diving and long boat tours, are curtailed. For photographers the storm-scoured skies create dramatic seascapes, but expect cancelled trips and to prioritize safety when seas are rough.

Cardamom Mountains & Southwest (Koh Kong, Cardamom range, Bokor, Botum Sakor)

September remains very wet and access to many remote conservation areas is difficult; however, low tourist numbers mean private experiences are possible if you accept logistical unpredictability. Road travel to Bokor and Botum Sakor can be disrupted by landslips; check local guidance before attempting long transfers. Waterproof packs and patience are essential if you travel now.

Northeast Uplands (Ratanakiri, Mondulkiri - highlands, waterfalls, ethnic villages)

September remains within the heavy monsoon window and flooding risk is notable in lower valleys; however, waterfall volumes are spectacular and the region is at its greenest. Travel requires patience and flexible timing; many guided tours operate on shorter, safer routes. Bring sturdy boots and a good insect net for homestays - mosquitos are plentiful after dusk.