January weather forecast
Dehiwala, Sri Lanka

The start of the year in Dehiwala, Sri Lanka, boasts mild climate with comfortable temperatures. January's weather indicates a favourable blend of moderate warmth and pleasing humidity, making it an enjoyable month for locals and visitors alike. The temperature marginally decreases from the previous month, exhibiting a downward trend. Neverlheless, it's worth noting the highest sea temperature, hitting a peak of 27.7°C (81.9°F). Moving forward, residents can anticipate a slight rise in temperature in the coming month, February.

Temperature

The advent of January in Dehiwala brings an average high-temperature of a tropical 30.3°C (86.5°F), almost identical to the preceding month. Dehiwala records an average temperature drop to a moderately hot 23.3°C (73.9°F) in January.

Heat index

In January, the heat index is estimated at a sweltering 37°C (98.6°F). Extra precautions are necessary, heat cramps and heat exhaustion are plausible outcomes. Extended activity could lead to heatstroke.
Heat index specifics point out values are for conditions of shade and a slight breeze. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', binds temperature metrics with humidity values to give a sense of the actual warmth. Factors including metabolic differences, physical activity, and clothing are additional elements that influence the individual's temperature experience. With direct sunlight, be aware that it might enhance the heat sensation, raising the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Juveniles are regularly less conscious of the need to recuperate and rehydrate. Thirst is a tardy symptom of dehydration - hydration, especially during lengthy physical activities, should be maintained.
In high temperatures, perspiration kicks in, allowing the human body to cool down through the evaporation of sweat. With high air temperature and humidity (high heat index) conditions, sweat production is restricted, leading to an amplified perception of heat. When body heat isn't effectively managed, risks of dehydration and overheating amplify.

Humidity

January is the least humid month, with an average relative humidity of 74%.

Rainfall

The month with the least rainfall is January, when the rain falls for 12.7 days and typically collects 44mm (1.73") of precipitation.

Sea temperature

In Dehiwala, the average seawater temperature in January is 27.7°C (81.9°F).
Note: Water temperature ranging between 25°C (77°F) and 29°C (84.2°F) is considered very warm and pleasing for everyone. It allows for enjoyable water activities over extended periods without discomfort.

Daylight

In January, the average length of the day in Dehiwala is 11h and 47min.
On the first day of January, sunrise is at 06:21 and sunset at 18:05. On the last day of the month, sunrise is at 06:28 and sunset at 18:18 +0530.

Sunshine

With an average of 9.2h of sunshine, January has the most sunshine of the year in Dehiwala.

UV index

January through April, June, July, September, November and December, with an average maximum UV index of 7, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV radiation for average individuals.
Note: The UV index of 7 in January translates into these instructions:
Steer clear of overexposure. Fair-skinned individuals can be scorched in less than 20 minutes. The time between 10 a.m. and 4 p.m. is when UV radiation is at its peak. Limit exposure to direct sunlight during these hours. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Warning! The reflection of sand and water increases the UV dose.