Climate Overview
The climate in Siem Reap is hot. The average annual temperature is 29°C and approximately 1380mm of precipitation falls per year. September is the wettest month, receiving around 260mm of rainfall. Siem Reap is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: April, March, May. The coldest months are December, January, February, when temperatures can drop to 23°C.
Temperature
Siem Reap sees moderate temperature variation throughout the year, ranging from 23°C to 35°C. April is the hottest month, with daytime highs reaching 35°C and an average of 31°C. December is the coolest month, with minimum temperatures around 23°C and an average of 26°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows.
Precipitation
Siem Reap is a fairly wet location, receiving approximately 1380mm of precipitation annually, which averages out to around 115mm per month. The wettest month is September, averaging 260mm of rainfall. October and July also tend to see above-average precipitation. The driest month is February, with just 16mm. That's 244mm less than September, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.
Wind
Siem Reap is relatively calm, with an average annual wind speed of 8km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is July, averaging 11km/h, though still comfortable for most outdoor activities. The calmest conditions occur in October, with average winds dropping to 7km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 4km/h gap between the calmest and windiest months.
Seasons
3 days until Autumn
It is currently summer in Siem Reap, which began on June 21, 2026. Siem Reap is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in April at around 35°C, while the coldest stretch bottoms out in December near 23°C. Autumn is next, beginning on September 23, 2026 (3 days from now).
Spring
Temperatures range from 26 to 35°C. Precipitation is moderate at around 260mm for the season, averaging 87mm per month. Winds are generally light, averaging 7km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 27 to 34°C. Rainfall is heavy, totalling around 457mm across the season with a monthly average of 152mm. Winds are generally light, averaging 10km/h. Light, breathable clothing is ideal. Perfect conditions for outdoor activities.
Autumn
Temperatures range from 24 to 32°C. Rainfall is heavy, totalling around 604mm across the season with a monthly average of 201mm. Winds are generally light, averaging 8km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 23 to 33°C. Rainfall is relatively light, with around 59mm over the season and a monthly average of 20mm. Winds are generally light, averaging 8km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Monthly Climate Data
The table below shows monthly climate averages for Siem Reap based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
