Sea temperature in Sri Lanka
Live water temperatures and swimming conditions across 13 beaches on the Sri Lanka coast.
Best time to swim in Sri Lanka
The sea in Sri Lanka peaks in February, when the water averages around 25°C.
The main swimming season runs from January – December, when surface temperatures stay comfortable for extended sessions.
On average, 12 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
The coldest month is typically July at around 20°C, when cold-water swimmers dominate the coast.
Sri Lanka sits in the Southern Hemisphere, so the warmest sea coincides with the December–February summer and the coolest with July–August.
Sri Lanka sea temperature history
Long-term climatology for Sri Lanka shows an annual mean sea temperature of 22°C, ranging from 20°C in winter to 25°C at the summer peak.
The seasonal swing is roughly 5°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.
Recent decades have trended slightly warmer at Sri Lanka, in line with regional sea-surface temperature records for the wider basin.
Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.
Values are area averages; individual beaches vary by exposure and depth.
Sri Lanka sea temperature: frequently asked questions
What is the warmest month to swim in Sri Lanka?
February is the warmest month in Sri Lanka, when the sea averages about 25°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Sri Lanka?
The coldest month in Sri Lanka is typically July, when the water averages around 20°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Sri Lanka without a wetsuit?
The main swimming season in Sri Lanka runs from January – December — about 12 months a year when the sea sits above 20°C, the level most swimmers describe as pleasant without a wetsuit.
Do I need a wetsuit in Sri Lanka?
Outside peak summer the water in Sri Lanka drops toward 20°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.
What is the average sea temperature in Sri Lanka?
The long-term annual mean sea temperature in Sri Lanka is about 22°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Sri Lanka?
The live reading at the top of this page shows the current sea temperature in Sri Lanka, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Sri Lanka sea temperature by month
Average sea temperatures around Sri Lanka for every month of the year, based on long-term Open-Meteo marine climatology.
| Month | Average sea | Swimming comfort |
|---|---|---|
| January | 24.0°C | Warm swimming |
| February ⭐ | 25.0°C | Warm swimming |
| March | 24.0°C | Warm swimming |
| April | 23.0°C | Pleasant swimming |
| May | 22.0°C | Pleasant swimming |
| June | 21.0°C | Pleasant swimming |
| July | 20.0°C | Swimmable, refreshing |
| August | 20.0°C | Swimmable, refreshing |
| September | 21.0°C | Pleasant swimming |
| October | 22.0°C | Pleasant swimming |
| November | 23.0°C | Pleasant swimming |
| December | 24.0°C | Warm swimming |
Monthly figures are modelled climatology averages, not live readings. How accurate is our data?
Warmest beaches in Sri Lanka right now
| Beach | Region | Sea | Swim score |
|---|---|---|---|
| Weligama Beach | Southern | 28.6°C | Excellent |
| Tangalle Beach | Southern | 28.5°C | Excellent |
| Hikkaduwa Beach | Southern | 27.7°C | Excellent |
| Pasikuda Beach | Eastern | 27.5°C | Excellent |
| Negombo Beach | Western | 27.5°C | Excellent |
| Uppuveli Beach | Eastern | 27.4°C | Excellent |
| Mount Lavinia Beach | Western | 27.4°C | Excellent |
| Nilaveli Beach | Eastern | 21.7°C | Excellent |
| Mirissa Beach | Southern | 21.1°C | Excellent |
| Unawatuna Beach | Southern | 21.1°C | Excellent |
| Arugam Bay | Eastern | 20.9°C | Excellent |
| Bentota Beach | Galle | 20.8°C | Excellent |
| Hiriketiya Beach | Southern | 20.5°C | Excellent |
Sea temperature in Sri Lanka — FAQ
How warm is the sea in Sri Lanka in September?
The sea off Sri Lanka averages about 21.0°C in September, based on long-term monthly averages for this coast.
When is the best time to swim in Sri Lanka?
Sri Lanka is warmest in February (around 25.0°C) and coldest in July (around 20.0°C). There are typically 8 months a year when the water sits above 22°C.
What is the average yearly sea temperature in Sri Lanka?
Across all twelve months, the sea in Sri Lanka averages about 22.4°C.
Do you need a wetsuit to swim in Sri Lanka?
In peak season (around February, ~25.0°C) most swimmers are comfortable without a wetsuit. Outside summer, when the water drops toward 20.0°C, a 3/2mm to 5/4mm wetsuit is recommended.
Which beach in Sri Lanka has the warmest sea right now?
Hikkaduwa Beach typically has the warmest sea in September, while Hiriketiya Beach is the coolest of the featured beaches. Live readings for every beach are listed on this page.