January weather forecast
Kalutara, Sri Lanka

Kalutara experiences a tropical climate consistent with the rest of Sri Lanka in January. Warm temperatures ranging from 23.4°C (74.1°F) to 30.3°C (86.5°F) give way to an excellent beach weather. Sitting above the equator, Kalutara enjoys longer daylight hours approximated at 11.8 hours and a relative humidity of 75%. January marks the start of the year with expected rainfall amounting to 25mm (0.98") which falls within a span of 8.9 days. Seasoned travelers know this as an ideal time for outdoor activities before the heavy rains.

Temperature

January reports an average high-temperature of a hot 30.3°C (86.5°F), slightly varied from December's 29.7°C (85.5°F). In the month of January, Kalutara experiences an average low-temperature of 23.4°C (74.1°F).

Heat index

In January, the heat index is estimated at a fiery hot 37°C (98.6°F). Take extra safety measures to prevent heat exhaustion and heat cramps. Heatstroke could follow lengthy activity.
Understanding the heat index involves considering values for shaded locales with light wind. The heat index may scale up by 15 Fahrenheit (8 Celsius) degrees with direct sun exposure.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is a fusion of air temperature and moisture levels to demonstrate the sensation of heat. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. You should know that direct sun exposure can heighten weather effects, potentially elevating the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Typically, children face more danger than adults as they usually perspire less. Their larger skin surface relative to their small bodies and increased heat output from their activities enhance their risk.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. With higher relative humidity, the rate of evaporation is reduced, resulting in increased heat retention in the body compared to drier air. 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 75%, are the least humid months in Kalutara, Sri Lanka.

Rainfall

January is the month with the least rainfall in Kalutara. Rain falls for 8.9 days and accumulates 25mm (0.98") of precipitation.

Sea temperature

In Kalutara, Sri Lanka, in January, the average water temperature is 27.7°C (81.9°F).
Note: For any water activity, temperatures between 25°C (77°F) and 29°C (84.2°F) are deemed excellent and extremely satisfying for enduring periods.

Daylight

In Kalutara, Sri Lanka, the average length of the day in January is 11h and 47min.
On the first day of the month, sunrise is at 06:20 and sunset at 18:05. On the last day of January, 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.

UV index

January through April, July, September through 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 threat to health from exposure to the Sun's UV radiation for the ordinary person.
Note: In January, the UV index of 7 transforms into the following advice:
Deter overexposure. Protecting against the sun's effects is essential. During the period from 10 a.m. to 4 p.m., UV radiation is highest. Try to avoid direct sunlight during these hours. 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. Caution! The mirror effect of sand and water ups the UV radiation strength.