Siem Reap has a tropical monsoon climate, classified as Am in the Köppen system. The warmest month is March with an average high of 34°C, while the coldest month is January with lows dropping to 21°C. The annual temperature range of 13°C indicates a relatively stable climate year-round.
The driest month is January with only 2 rain days and 8mm of precipitation. For travellers, January through to the following month typically offers the best balance of warm temperatures and dry conditions. Average humidity ranges from 82% to 82% throughout the year.
Best Time to Visit Siem Reap
Based on temperature and rainfall data, the best months to visit Siem Reap are January, December, February. These months offer the most comfortable temperatures with relatively low rainfall, ideal for sightseeing and outdoor activities.
In March, Siem Reap experiences average highs of 34°C (93°F) and lows of 25°C (77°F). Expect around 9 rainy days and 11 hours of sunshine per day, with humidity averaging 82%. The 9°C gap between daytime and overnight temperatures is worth planning around: light layers work for most visitors during the day, but an overshirt or cardigan handles the cooler evenings. UV index averages 6, so sun protection is advisable on clear days.
Siem Reap typically sees 9 rainy days in March, with total precipitation of around 55mm. Rain is moderate and manageable. Showers tend to pass quickly, and a light rain layer or foldable umbrella is sufficient protection for most days. For context, the driest month in Siem Reap typically sees 4-6 fewer rain days than March.
Pack lightweight, breathable clothing (linen or cotton), a wide-brim sun hat, SPF 50+ sunscreen, and a refillable water bottle for Siem Reap in March. The 34°C daytime heat demands sun protection during midday hours, typically 11am to 4pm. A compact travel umbrella is also worth packing, as 9 rainy days means afternoon showers are a real possibility. Quick-dry synthetic fabrics are preferable to cotton in 82% humidity.
March is a reasonable time to visit Siem Reap. Expect 9 rainy days, so pack a light rain layer for flexibility. Average temperatures of 34°C make outdoor exploration comfortable during the dry periods. With 11 daily sunshine hours, there are reliable windows of good weather to plan outdoor activities around, even if the month is not the driest on the calendar.
The average high temperature in Siem Reap in March is 34°C (93°F), and the average low is 25°C (77°F). The mean daily temperature is approximately 30°C (85°F). The day-to-night range of 9°C is moderate, meaning a single light jacket covers most situations. These are 30-year climate normals based on the 1991 to 2020 reference period; individual years will vary, particularly in transitional months like spring and autumn.
The best month to visit Siem Reap is generally January. January offers the most sunshine at 11 hours per day and only 2 rainy days. Average temperatures reach 31°C, making it comfortable for sightseeing, outdoor dining, and exploring the city. If your travel dates are flexible, planning your trip around January gives you the best chance of dry, bright weather.
March is shoulder or low season in Siem Reap, meaning fewer tourists and generally lower prices than peak months. With 11 sunshine hours and 9 rainy days, the weather is less of a draw for mass tourism. This is an advantage for travellers who prefer a quieter, more relaxed experience with shorter queues and easier accommodation availability.
In March, Siem Reap suits a range of activities thanks to warm temperatures of 34°C. Mix of indoor and outdoor activities works well given the moderate chance of rain. Top options include exploring historic neighbourhoods, visiting museums and galleries, local food markets, and day trips to surrounding areas. With 11 hours of sunshine, parks and waterfront walks are particularly enjoyable.