May weather forecast
Kalutara, Sri Lanka

In May, Kalutara transitions into the monsoon season, marked by an upsurge in humidity and rainfall. This month records the highest rainfall of 303mm (11.93"), indicating the peak of the rainy season. Despite the high levels of precipitation, the temperatures remain relatively constant and warm. With continuous rainfall and cloudiness, May sees a dip in sunshine hours disrupting the well-known bright days of Kalutara. Therefore, this month is less favorable for outdoor activities compared to the previous four months.

Temperature

May's arrival in Kalutara brings an average high-temperature of a still tropical 30.2°C (86.4°F), demonstrating subtle variation from the preceding month. In Kalutara, a slight decrease from the daytime peak is noted during the month of May, with an average low-temperature of 26.3°C (79.3°F).

Heat index

May's average heat index is estimated at a torrid 39°C (102.2°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Realize that the values for the heat index are set for shaded places and light winds. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', is a composite of temperature and humidity figures to convey how warm it feels. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. It is important to note that direct sunlight can intensify the weather impact, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Kids often lack the knowledge about the necessity to take breaks and consume liquids. Thirst, as a late symptom of dehydration, necessitates the maintenance of hydration, particularly during enduring physical activities.
Sweat evaporation plays a crucial role in cooling the human body, a process enabled by perspiration. Increased relative humidity slows down evaporation, thereby decreasing the rate of heat removal from the body, culminating in a sensation of overheating. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.

Humidity

The average relative humidity in May is 81%.

Rainfall

In Kalutara, in May, it is raining for 28 days, with typically 303mm (11.93") of accumulated precipitation. In Kalutara, Sri Lanka, during the entire year, the rain falls for 273.8 days and collects up to 2059mm (81.06") of precipitation.

Sea temperature

In May, the average sea temperature is 29.3°C (84.7°F).
Note: Ideal surface water temperatures for any water activity fall between 25°C (77°F) and 29°C (84.2°F), offering maximum enjoyment for lengthened periods.

Daylight

In May, the average length of the day is 12h and 25min.
On the first day of the month, sunrise is at 05:56 and sunset at 18:17. On the last day of May, in Kalutara, sunrise is at 05:53 and sunset at 18:22 +0530.

Sunshine

In Kalutara, Sri Lanka, the average sunshine in May is 8.7h.

UV index

May, June and August, with an average maximum UV index of 6, are months with the lowest UV index in Kalutara. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index, 6 in May, converts into the following recommendations:
Uphold preventive measures and conform to sun safety guidelines. Defending against skin and eye harm is crucial. The Sun's UV radiation is most potent between 10 a.m. and 4 p.m. Try to limit direct exposure to the Sun during this period. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Be careful! The Sun's UV radiation is accentuated by reflecting off sand and water.