May weather forecastChilaw, Sri Lanka
May
Weather in May
May, the last month of the spring in Chilaw, is also a hot month, with temperature in the range of an average high of 30.8°C (87.4°F) and an average low of 26.4°C (79.5°F).Temperature
Chilaw's average high-temperature in May sits at a still hot 30.8°C (87.4°F), showing little difference from the previous month. A consistent average low-temperature of 26.4°C (79.5°F), with a minor variance from the daytime highs, is noted in Chilaw during the nights of May.Heat index
The average heat index in May is appraised at a blistering 40°C (104°F). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.Metrics for the heat index primarily focus on shaded spots and light wind conditions. Being exposed to direct sunshine might trigger a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', stands as a testimony to how temperature and humidity combine to impact our sense of warmth. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Juveniles often do not understand the need to recuperate and rehydrate. Thirst is a delayed symptom of dehydration - hence, it is vital to maintain hydration, particularly during ongoing physical activities.
Evaporation of sweat is the main factor behind the cooling effect of perspiration in the human body. Increased relative humidity slows down evaporation, thereby decreasing the rate of heat removal from the body, culminating in a sensation of overheating. Heat-related disorders may develop if heat gain in the body overshadows its cooling capacity, leading to elevated temperatures.
Humidity
In May, the average relative humidity is 80%.Rainfall
In Chilaw, in May, it is raining for 26.3 days, with typically 204mm (8.03") of accumulated precipitation. In Chilaw, during the entire year, the rain falls for 265.4 days and collects up to 1744mm (68.66") of precipitation.Sea temperature
In Chilaw, Sri Lanka, the average seawater temperature in May is 29.4°C (84.9°F).Note: Water temperatures from 25°C (77°F) to 29°C (84.2°F) make swimming, diving, and similar activities highly pleasurable and enjoyable for long periods without discomfort.
Daylight
In Chilaw, the average length of the day in May is 12h and 28min.On the first day of May, sunrise is at 05:56 and sunset at 18:19. On the last day of the month, sunrise is at 05:52 and sunset at 18:24 +0530.
Sunshine
In May, the average sunshine is 8.8h.UV index
May, June, August and October, with an average maximum UV index of 6, are months with the lowest UV index. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for the average person.Note: A maximum daily UV index of 6 during May morphs into the following directions:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Be mindful! Sand and water reflections can up the Sun's UV exposure.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Chilaw, Sri Lanka
- Average high temperature in May: 30.8°C
The warmest month (with the highest average high temperature) is March (32.1°C).
The month with the lowest average high temperature is July (29.2°C).
- Average low temperature in May: 26.4°C
The month with the highest average low temperature is May (26.4°C).
The coldest month (with the lowest average low temperature) is January (22.8°C).
Average pressure in May
Chilaw, Sri Lanka
- Average pressure in May: 1008.4mbar
The month with the highest atmospheric pressure is January (1011.7mbar).
The months with the lowest atmospheric pressure are May and June (1008.4mbar).
Average wind speed in May
Chilaw, Sri Lanka
- Average wind speed in May: 15.5km/h
The windiest month (with the highest average wind speed) is June (18.3km/h).
The calmest month (with the lowest average wind speed) is March (9.1km/h).
Average humidity in May
Chilaw, Sri Lanka
- Average humidity in May: 80%
The months with the highest relative humidity are June, July and August (82%).
The months with the lowest relative humidity are January and February (73%).
Average rainfall in May
Chilaw, Sri Lanka
- Average rainfall in May: 204mm
The wettest month (with the highest rainfall) is June (231mm).
The driest month (with the least rainfall) is January (29mm).
Average rainfall days in May
Chilaw, Sri Lanka
- Average rainfall days in May: 26.3 days
The month with the highest number of rainy days is August (28.4 days).
The month with the least rainy days is January (9.7 days).
Average sea temperature in May
Chilaw, Sri Lanka
- Average sea temperature in May: 29.4°C
The best month for swimming (with the highest average sea temperature) is April (29.6°C).
The coldest month (with the lowest average sea temperature) is August (27°C).
Average daylight in May /
Average sunshine in May
Chilaw, Sri Lanka
- Average daylight in May: 12h and 30min
The month with the longest days is June (Average daylight: 12h and 36min).
The month with the shortest days is December (Average daylight: 11h and 42min).
- Average sunshine in May: 8h and 48min
The months with the most sunshine are January, February, March and April (Average sunshine: 9h and 12min).
The month with the least sunshine is November (Average sunshine: 6h and 36min).
Average sunshine days in May
Chilaw, Sri Lanka
- Average sunshine days in May: 3.6 days
The month with the most sunshine days is January (20 days).
The month with the least sunshine days is August (1.2 days).
Average UV index in May
Chilaw, Sri Lanka
- Average UV index in May: 6
The months with the highest UV index are January, February, March, April, July, September, November and December (UV index 7).
The months with the lowest UV index are May, June, August and October (UV index 6).
Average cloud cover in May
Chilaw, Sri Lanka
- Average cloud cover in May: 52
The month with the most cloud cover is June (Cloud cover 57).
The month with the least cloud cover is January (Cloud cover 21).
Average visibility in May
Chilaw, Sri Lanka
- Average visibility in May: 9km
The months with the highest visibility are January, February, March, April, June, July, September and December (10km).
The months with the lowest visibility are May, August, October and November (9km).





