Can you dive Sri Lanka all year?

Not everywhere at once. Counting both areas, 10 months of the year have somewhere at its best; the rest are workable but off peak.

How warm is the water in Sri Lanka?

27 to 30 °C across the year, depending on the area and the month. Each area's page gives its own month-by-month temperatures.

Indian Ocean

Best Time to Dive in Sri Lanka

2 dive areas, each scored on its own. The season peaks May–September at East (Trincomalee), and December–April at West (Hikkaduwa). Between them there is somewhere worth diving in 10 months of the year.

The 2 dive areas in Sri Lanka, compared month by month
	J	F	M	A	M	J	J	A	S	O	N	D
East (Trincomalee)	January: Off season	February: Off season	March: Off season	April: Good	May: Good	June: Good	July: Good	August: Good	September: Good	October: Off season	November: Off season	December: Off season
West (Hikkaduwa)	January: Good	February: Good	March: Good	April: Good	May: Off season	June: Off season	July: Off season	August: Off season	September: Off season	October: Off season	November: Off season	December: Good

Off season Good

Sri Lanka compared

Side by side

The 2 dive areas in Sri Lanka, compared on season, water, visibility and how they are dived
Dive area	Best time	Water	Visibility	Dived from	Suits
East (Trincomalee)	May–Sep	27–30 °C	5–25 m	day boat	Open Water
West (Hikkaduwa)	Dec–Apr	28–30 °C	0–20 m	day boat	Open Water

Water and visibility are the whole year's range at each area, coldest month to warmest. Visibility is estimated from satellite chlorophyll-a.

Which area to pick

East (Trincomalee): The only one in season from May to September. It has the clearest water, up to 25 m.
West (Hikkaduwa): The only one in season from December to April. It has the lowest visibility, 0–20 m.

Sri Lanka month by month

Two or more areas are good at once in April: the time to combine them in one trip.

Jan–Mar: Good at West (Hikkaduwa). Off season at East (Trincomalee).
Apr: Every area is good.
May–Sep: Good at East (Trincomalee). Off season at West (Hikkaduwa).
Oct–Nov: Nowhere at its best.
Dec: Good at West (Hikkaduwa). Off season at East (Trincomalee).

East (Trincomalee)

May–Sep

Closed November to February. The best conditions run May to September, when the downpours ease — 2 days a month of heavy rain instead of 5. Too few records to show a wildlife season, so the weather picks the month. The full season runs April to September.

East (Trincomalee) conditions month by month
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
January: Off season	February: Off season	March: Off season	April: Good	May: Good	June: Good	July: Good	August: Good	September: Good	October: Off season	November: Off season	December: Off season

Off season Good

Water: 27–30 °C
Wear: 3 mm full suit
Dived from: day boat
Suits: Open Water

East (Trincomalee) month by month →

West (Hikkaduwa)

Dec–Apr

Aim for December to April for the calmest water — seas top 1.5 m on 7% of days, against 79% the rest of the year. The marine life holds steady all year, so the weather picks the month.

West (Hikkaduwa) conditions month by month
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
January: Good	February: Good	March: Good	April: Good	May: Off season	June: Off season	July: Off season	August: Off season	September: Off season	October: Off season	November: Off season	December: Good

Good Off season

Water: 28–30 °C
Wear: 3 mm full suit
Dived from: day boat
Suits: Open Water

West (Hikkaduwa) month by month →

Diving in Sri Lanka: common questions

When is the best time to dive Sri Lanka?: It depends which area. The season peaks May–September at East (Trincomalee), and December–April at West (Hikkaduwa).
Can you dive Sri Lanka all year?: Not everywhere at once. Counting both areas, 10 months of the year have somewhere at its best; the rest are workable but off peak.
How warm is the water in Sri Lanka?: 27 to 30 °C across the year, depending on the area and the month. Each area's page gives its own month-by-month temperatures.