December weather forecast
Phnom Penh, Cambodia

December in Phnom Penh signals the full retreat of the monsoon, making way for drier and sunnier days. The city sees a substantial decrease in rainfall to 80mm (3.15"), which teamed up with an increase in the sunshine hours to 7.8 daily, brings a sense of lightness to the city’s ambiance. The average high temperature drops slightly, offering more comfortable conditions. The weather patterns venture towards a drier profile with a decrease in both rainfall and humidity, which matches the January’s value of 73%. The return of the dry season is a mark of festive times in the city, steering towards Christmas and New Year celebrations.

Temperature

The commencement of December notes an average high-temperature of a tropical 30.1°C (86.2°F), exhibiting little difference from the previous month. Nighttime temperatures in Phnom Penh hover around an average low of 21.7°C (71.1°F) in December.

Heat index

In December, the average heat index is evaluated at a sweltering 36°C (96.8°F). Adopt enhanced safety measures, heat exhaustion and heat cramps could occur. Continuous activity may induce heatstroke.
When referencing the heat index, its values are suitable for shady environments and light breezes. Direct sunlight can cause a surge in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', blends air temperature and moisture content to represent the felt temperature to humans. Factors such as metabolic variation, pregnancy, and physical activity play a role in one's impression of weather. Do note, being directly under sun rays can amplify the heat you feel, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
Perspiring is how the human body naturally cools down, as sweat's evaporation takes away excess heat. With a high level of moisture in the air, the evaporation process becomes less efficient, preventing the body from cooling down efficiently and resulting in a sensation of overheating. When the body's heat gain surpasses its removal capacity, body temperature starts to climb, leading to potential heat-related ailments.

Humidity

The average relative humidity in December is 73%.

Rainfall

In Phnom Penh, during December, the rain falls for 4.8 days and regularly aggregates up to 80mm (3.15") of precipitation. In Phnom Penh, during the entire year, the rain falls for 153.4 days and collects up to 1636mm (64.41") of precipitation.

Daylight

With an average of 11h and 30min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 06:04 and sunset at 17:34. On the last day of December, in Phnom Penh, sunrise is at 06:19 and sunset at 17:47 +07.

Sunshine

In December, the average sunshine is 7.8h.

UV index

The months with the lowest UV index in Phnom Penh are January, November and December, with an average maximum UV index of 10. A UV Index estimate of 8 to 10 represents a very high threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: In December, the maximum UV index of 10 suggests this advice:
Don't neglect protection; skin and eyes can be burned swiftly if left exposed. The Sun's UV radiation is most potent between 10 a.m. and 4 p.m. Try to limit direct exposure to the Sun during this period. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Apply and frequently reapply a broad-spectrum SPF 30+ sunscreen after every two hours, or immediately after a swim or outdoor exercise.