Dehiwala Weather in May

Dehiwala in May averages 31°C (88°F) during the day and 26°C (79°F) at night. May is part of the rainy season, so frequent rainfall is typical.

Rainfall in Dehiwala in May

As part of the rainy season, Dehiwala sees around 14 days of rain in May, with an average of 298 mm (12 in). Rainy season showers here are typically intense, often clearing quickly but coming down hard while they last.

Temperature in Dehiwala in May

Temperatures in Dehiwala in May top out at 31°C (88°F) and drop to 26°C (79°F) overnight. If you're spending a lot of time outdoors, it helps to plan around the warmer part of the day. Nights are warm at 26°C (79°F), which can make sleeping uncomfortable. Keeping windows open or using a fan can help. A cold shower before bed is also a good way to cool down.

Sunshine in Dehiwala in May

There are approximately 202 hours of sunshine this month, despite being the rainy season. Rain often arrives in the late afternoon or evening, keeping mornings and early afternoons sunny. Even during the wet season, it could still be a nice time to visit.

Wind Speed in Dehiwala in May

May sees wind speeds averaging 2 m/s (4 knots). You'll typically experience pleasant light breezes that move leaves slightly and feel refreshing. As an average, expect variation from very calm days to periods with more apparent air movement.

Average water temperature in May

With water at 28°C (82°F), you can expect warm, pleasant conditions for any water activity. There's no adjustment period — it feels comfortable straight away.

May in Dehiwala can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.

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• February
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• May
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For a detailed overview over the year and the best time to visit Sri Lanka, check out our Dehiwala's climate page.

Dehiwala Temperature in May

Min Temperature 26°C (79°F)  

Max Temperature 31°C (88°F)  

Water Temperature 28°C (82°F) *  

Chance of Rain 46%  

Precipitation 298 mm (12 in)  

Rainy days 14 days  

Humidity 77% *  

Windspeed 2 m/s (4 knots) *  

Sunshine 202 hours *  

Percentage Sunshine *  

* Data from: Colombo, Sri Lanka (5 KM, 3 Miles).

Daily Historical Temperatures

44-year average (1976-2025)

Based on our historical records, temperatures in Dehiwala typically stay consistent throughout May, with daily highs averaging around 31°C (88°F). Nights are warm, with lows around 26°C (79°F).

Average temperatures in May

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Daily Historical Precipitation

44-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in May

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Historical weather for Dehiwala in May

Browse day-by-day weather records for Dehiwala spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Historical weather Temperatures Precipitation

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‹ January February March April May June July August September October November December ›

Dehiwala historical weather extremes in May

Based on weather observations in Dehiwala between 1995 and 2026, these are the recorded extremes during May.

• The hottest May day on record in Dehiwala reached 37°C (99°F) (May 29, 1998).
• The lowest daytime temperature in May was 25°C (77°F), recorded on May 7, 1997.
• The coldest night in May in Dehiwala was on May 13, 2003, with a minimum of 20°C (68°F).

What to Wear in Dehiwala in May

Warm weather calls for comfortable, breathable clothing in May. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Also bring a poncho, it will rain a lot! Waterproof everything you can. The water temperature sits at about 28°C (82°F), making it perfect for swimming and water activities. Don't forget to pack your favorite swimwear and perhaps some snorkel gear. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in Dehiwala in May

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

8/10

Cycling

7/10

Walking

7/10

Camping

7/10

Outdoor sports

7/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Sri Lanka, check out our Dehiwala's climate page.

More climate data for Dehiwala

Temperature Rainfall Sunshine Humidity Wind Speed Water Temp

See the full Dehiwala climate overview or explore weather in Sri Lanka.