April weather forecast
Polonnaruwa, Sri Lanka

April, like March, is another tropical spring month in Polonnaruwa, Sri Lanka, with an average temperature fluctuating between 23.5°C (74.3°F) and 34.9°C (94.8°F).

Temperature

With an average high-temperature of 34.9°C (94.8°F) and an average low-temperature of 23.5°C (74.3°F), April is the warmest month.

Heat index

In April, the average heat index is computed to be a blazing hot 52°C (125.6°F). Be wary: Heat exhaustion and heat cramps are highly anticipated. With continued activity, heatstroke is very likely.
Take into consideration that the heat index values are calculated for shade and light wind conditions. 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', 'felt air temperature', 'feels like', or 'apparent temperature', is a measure of how hot it feels when the actual air humidity is factored in. Additional factors like activity, differences in body mass, height, and shape, pregnancy, and wind affect individual temperature impact. 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. 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.
To prevent overheating and help regulate its internal temperature, the human body sweat and rely on the evaporation to cool down. When the relative humidity is high, the evaporation rate is reduced. The warmth is removed from the body at a lower rate, causing the body to retain more heat than it would in dry air. 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 April, the average relative humidity in Polonnaruwa is 73%.

Rainfall

In Polonnaruwa, during 23.6 rainfall days, 103mm (4.06") of precipitation is typically accumulated. Throughout the year, in Polonnaruwa, there are 196.8 rainfall days, and 943mm (37.13") of precipitation is accumulated.

Daylight

The average length of the day in April is 12h and 18min.
On the first day of the month, sunrise is at 06:04 and sunset at 18:15. On the last day of April, sunrise is at 05:51 and sunset at 18:15 +0530.

Sunshine

The average sunshine in April is 10.1h.

UV index

The months with the highest UV index in Polonnaruwa are February through October, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV rays for ordinary individuals.
Note: The daily maximum UV index of 7 in April interpret into the following advice:
Take precautions against overexposure. Protection against sun damage is needed. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.