Siem Reap Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Siem Reap, Siem Reap Province, Cambodia. Long-term data from 1990 to 2020 was used to calculate these averages. Now, let's break down all the details for a clearer picture.

Siem Reap has a relatively rainy climate with high precipitation levels, averaging 1470 mm (58 in) of rainfall annually. Despite the high annual total, it does experience a distinct dry and rainy season during certain months. Examine our detailed charts below to understand these seasonal patterns.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

Siem Reap can be quite wet during September, receiving approximately 286 mm (11 in) of precipitation over 18 rainy days.

In contrast January, experiences much drier conditions, with 9.8 mm (0.4 in) of rainfall, spread across a single rainy day.

September, the wettest month, has a maximum daytime temperature of 33°C (91°F). During the driest month January you can expect a temperature of 33°C (91°F). For more detailed insights into the city's temperatures, visit our Siem Reap Temperature page.

Siem Reap's average annual precipitation is 1470 mm (58 in). Let's compare this to some popular worldwide tourist destinations:

Seville, Spain, experiences 541 mm (21 in) of rainfall annually, with wet winters and dry summers typical of southern Spain.

Osaka, Japan, experiences 1507 mm (59 in) of rainfall annually, spread across the year with wetter summers.

In Tokyo, Japan, the average annual precipitation is 1528 mm (60 in), with significant summer rains due to typhoon season.

Mumbai, India, experiences a tropical monsoon climate with 1860 mm (73 in) of annual rainfall, with the majority of precipitation happening during the monsoon season from June to September.

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

Precipitation has a very strong role in determining the local climate and ecosystem:

• Changing Rainfall Patterns: Global warming causes drastic changes in the patterns of rainfall. Some areas have been experiencing increased frequency and intensity of rainfall, while other areas experience longer dry spells or even droughts.
• Local Impacts: Many regions are experiencing heavier rainfall in the winter months and drier, hotter summers. This affects agriculture, water resources, and ecosystems.

• Mawsynram in India is noted as being the wettest place on earth, with over 11 meters (36 feet) of rain falling every year.
• In contrast, Antofagasta in Chile is among the driest places on the planet, getting less than 0.1mm (0.004 inches) per year, with some years recording virtually no rainfall.
• Nearly 1,650 thunderstorm cells are estimated over the planet at any given time.

For more detailed information about Siem Reap's weather, including sunshine hours, humidity levels, and temperature data, visit our Siem Reap Climate page.