January weather forecast and climate
Colombo, Sri Lanka

January in Colombo, Sri Lanka, is a tropical winter month, with average temperature ranging between max 30.8°C (87.4°F) and min 23.1°C (73.6°F).

Temperature

In January, the average high-temperature is almost the same as in December - a hot 30.8°C (87.4°F). The average low-temperature,, is 23.1°C (73.6°F).

Heat index

In January, the average heat index is calculated to be a very hot 38.3°C (100.9°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'apparent temperature', 'felt air temperature', or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. This effect is individual, with diverse people perceiving weather differently for numerous reasons (metabolic differences, pregnancy, wind), and activity. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. High relative humidity reduces the evaporation rate, resulting in a lower heat removal rate from the body, causing the perception of being overheated. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

January and February, with an average relative humidity of 74%, are the least humid months.

Rainfall

The month with the least rainfall in Colombo is January when the rain falls for 11.6 days and typically collects 40mm (1.57") of precipitation.

Sea temperature

In Colombo, in January, the average water temperature is 27.7°C (81.9°F).
Note: For any water activity, surface water temperatures between 25°C (77°F) and 29°C (84.2°F) are considered as excellent and extremely pleasant for lengthened periods.

Daylight

In January, the average length of the day in Colombo, Sri Lanka, is 11.8h.

Sunshine

January has the most sunshine of the year, with an average of 9.1h of sunshine.

UV index

January through April, July, September, November and December, with an average maximum UV index of 7, are months with the highest UV index in Colombo. A UV Index of 6 to 7 symbolizes a high threat to health from unprotected exposure to the Sun's UV rays for the average person.
Note: The average daily UV index of 7 in January transform into the following instructions:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.