April weather forecast
Colombo, Sri Lanka

In April, Colombo experiences the first major surge of rainfall in the year, shooting up to 137mm over 25.4 days. This increase coincides with the highest temperature peaks of 31.8°C, resulting in particularly humid and hot conditions. A slightly expanded daylight period allows for ample sightseeing time, despite the frequent rain showers. Moreover, the sea experiences a warming trend, perfect for swimmers and divers. However, the cloudy conditions, coupled with increased rainfall, may affect outdoor plans.

Temperature

Colombo's peak temperatures tend to occur in March and April, with an average high-temperature of 31.8°C.

Heat index

The heat index in April is computed to be a blistering 42°C. Adopt extra preventive measures, the occurrence of heat cramps and heat exhaustion is likely. Heatstroke may follow extended activity.
Evaluating the heat index requires understanding its values in the shade and with gentle winds. The heat index might be elevated by 15 Fahrenheit (8 Celsius) degrees due to direct sun exposure.
Note: The heat index, also known as 'real feel' or 'feels like', determines the feeling of heat when you account for the relative humidity. The influence of weather is personal, with varied individuals experiencing it differently due to differences in body mass, stature, and physical exertion levels. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Young ones often ignore the need to take a break and drink fluids. Thirst is a late-stage symptom of dehydration - hence, maintaining hydration, particularly during extended physical activities, is crucial.
To offset high temperatures, the human body releases sweat which, upon evaporation, cools it down. Heightened relative humidity interferes with the body's usual cooling mechanism by reducing evaporation, subsequently decreasing the body's cooling rate and increasing the sensation of heat. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

In Colombo, the average relative humidity in April is 77%.

Rainfall

In Colombo, in April, during 25.4 rainfall days, 137mm of precipitation is typically accumulated. In Colombo, Sri Lanka, during the entire year, the rain falls for 289.4 days and collects up to 2262mm of precipitation.

Sea temperature

April is the month with the warmest seawater in Colombo, with an average sea temperature of 29.6°C.
Note: For activities such as swimming and diving, temperatures between 25°C and 29°C are perceived as particularly pleasant and satisfying for prolonged periods without feeling uneasy.

Daylight

In Colombo, the average length of the day in April is 12h and 17min.
On the first day of the month, sunrise is at 06:08 and sunset at 18:20. On the last day of April, sunrise is at 05:56 and sunset at 18:18 +0530.

Sunshine

The average sunshine in April in Colombo, Sri Lanka, is 8.9h.

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. A UV Index value of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for average individuals.
Note: The average daily UV index of 7 in April transforms into the following instructions:
Inhibit overexposure. Warding off sun damage is of utmost importance. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is at its strongest, and remember that parasols or canopies do not offer full protection. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Alert! UV radiation becomes sharper due to reflections from sand and water.