Season
November to April. That's the window.
Dry season on the south coast is freediving season.
Sri Lanka has two monsoons, which means the "best" coast depends on the month. For Unawatuna and the south, the answer is straightforward: November through April. That is when we operate Lanka Freediving and when conditions are most reliable for courses and open-water sessions.
Month by month
November: Season opens. Seas settle after the southwest monsoon; fewer tourists than peak. Good visibility building.
December–January: Peak travel. Book courses and hotels early. Calm mornings, warm water 27–29°C.
February–March: Often excellent visibility and still dry. Our favourite teaching months.
April: Still diveable; occasional heat and humidity rising. Last weeks of our season.
May–October: Southwest monsoon affects this coast — more rain, less predictable seas. We do not run scheduled courses; some operators move to the east (Trincomalee) where season is inverted.
Water conditions
Expect 27–30°C water — most students fine in 3 mm or rash vest. Visibility on calm mornings often exceeds 15 m on reef sites. Afternoon wind can chop the surface; we schedule around it.
Planning your course
Wave 1 needs three days plus theory time before arrival. Discover fits a free half-day. The five-day retreat is best with a full week in country. Check which Molchanovs course fits your trip length.
Whales and weather
Whale-watching off Mirissa overlaps our season (roughly December–April). Combine with freediving if you have spare days — see the south coast top ten.