May weather forecast
Dehiwala, Sri Lanka

The arrival of May in Dehiwala manifests intensified weather conditions featuring pouring rains and soaring humidity levels. The city undergoes minor variances in climate from April, albeit with an evident increase in precipitation. Its noteworthy to pinpoint May's exceedingly high levels of rainfall totaling a massive 312mm (12.28"), the highest throughout the year. As May leaves its mark, Dehiwala readies itself for June's continued downpour and marginally cooler evenings.

Temperature

May ushers in an average high-temperature of a still hot 30.3°C (86.5°F) in Dehiwala, aligning closely with the preceding month. May nights in Dehiwala experience a minor temperature downturn to a warm 26.4°C (79.5°F).

Heat index

In May, the average heat index is estimated at a very hot 39°C (102.2°F). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.
When referencing the heat index, its values are suitable for shady environments and light breezes. The heat index could see an increase by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'feels like' or 'real feel', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. One's perception of weather can be shaped by other factors, involving metabolic differences, pregnancy, and physical exertion. Recognize that direct exposure to the sun can escalate the heat effect, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are highly important for children. Kids are generally in more danger than adults because they perspire less. Their large skin surface area compared to their small bodies and the excessive heat due to their actions raises their risk.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. In high relative humidity, the body's ability to evaporate heat is diminished, resulting in a heightened feeling of warmth. Overheating and potential dehydration arise when body heat gain eclipses its release capability.

Humidity

In May, the average relative humidity in Dehiwala is 81%.

Rainfall

In Dehiwala, during May, the rain falls for 28.4 days and regularly aggregates up to 312mm (12.28") of precipitation. In Dehiwala, during the entire year, the rain falls for 285.6 days and collects up to 2201mm (86.65") of precipitation.

Sea temperature

In Dehiwala, in May, the average water temperature is 29.3°C (84.7°F).
Note: For activities such as swimming and diving, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as particularly pleasant and satisfying for prolonged periods without feeling uneasy.

Daylight

In May, the average length of the day is 12h and 26min.
On the first day of the month, sunrise is at 05:56 and sunset at 18:18. On the last day of May, in Dehiwala, sunrise is at 05:53 and sunset at 18:23 +0530.

Sunshine

In May, the average sunshine is 8.6h.

UV index

May, August and October, with an average maximum UV index of 6, are months with the lowest UV index. A UV Index estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: The UV index of 6 during May translates into the following guidance:
Avert overexposure. Light-skinned people might experience burning in less than 20 minutes. Make an effort to avoid direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation, and note that objects like parasols or canopies might not offer full sun protection. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Notice! The reflection of water and sand increases the UV radiation significantly.