Sri Lanka's two monsoons, and which coast is dry when

Most monsoon countries have a wet season and a dry one, and the choice of when to go is simple. Sri Lanka is more complicated, and more forgiving. It sits in the Indian Ocean just north of the equator, in the path of two monsoons. One blows from the south-west in the middle of the year, and the other from the north-east around the turn of the year. The island is small, about four hundred and thirty kilometres from top to bottom. But it has a block of mountains in the south-centre, and those mountains catch the rain from whichever direction it comes. The result is that the south-west and the north-east of the country tend to have their wet seasons at different times, and a well-planned trip can stay on the dry side.

The rules of thumb are below. They are tendencies, not guarantees: monsoons arrive early, leave late and occasionally misbehave, and a tropical island gets the odd shower in any month.

The south-west monsoon: May to September

From roughly May to September, the south-west monsoon brings rain to the west and south coasts and to the western slopes of the hill country. This is the low season for the beaches south of Colombo, from Beruwala and Bentota down to Galle, where the sea is rough and the skies are often heavy. It doesn't rain all day, every day, but swimming is a less reliable pleasure.

On the other side of the mountains, the same months are the dry season. The east coast, from Trincomalee down to Arugam Bay, is at its best, with calm seas and plenty of sun. The Cultural Triangle in the north-central plains, home to the old royal cities of Anuradhapura and Polonnaruwa and the rock fortress of Sigiriya, lies in the island's dry zone and gets relatively little rain at this time of year.

The north-east monsoon: December to March

From around December, the pattern turns. The north-east monsoon brings rain to the north and east, while the west and south coasts, the hill country and much of the interior enjoy their driest, sunniest months. This is Sri Lanka's main season for visitors, and the reason is easy to see. The beaches of the south-west are calm, Galle's old Dutch fort is warm and bright, and the tea country around Nuwara Eliya has its clearest views. The Cultural Triangle is also generally pleasant, if hot, especially from January onwards.

Between the two monsoons come the inter-monsoon periods, around April and again around October and November. They bring afternoon thunderstorms to much of the island, and October and November are often among the wettest months of the year in many places. They are not a reason to stay away, as long as you don't mind an afternoon spent under a veranda watching the rain.

Planning around it

For most British visitors, whose holidays fall in the European winter, the answer is the classic route in the classic season. Start with the ancient cities and Sigiriya, climb to Kandy and the hill country, then finish on the beach at Beruwala or near Galle. From December to March, every stage of that is on the dry side of the island.

Just You's Sri Lanka, Pearl of the Indian Ocean, fifteen nights for solo travellers, follows that shape: from Colombo to Habarana, Sigiriya and Polonnaruwa, then Kandy and Nuwara Eliya, and on to the coast at Beruwala, with Galle and the turtle hatcheries of Kosgoda nearby.

Travelsphere's Highlights of Sri Lanka with Beruwala Beach Extension, fourteen nights, covers similar ground. It adds the elephants of Minneriya and Yala National Park in the dry south-east, where the wildlife is easier to see when the waterholes are low.

Explore Worldwide's Upgraded Discover Sri Lanka, twelve nights, adds the hill station of Ella and the pilgrimage town of Kataragama on the way down to Yala, Galle and the coast at Beruwala. It runs in most months from August to March. In August and September the ancient cities are on the dry side, though the western slopes of the hills can be wet.

The short version: for the west and south coasts, go between December and March. For the east coast, go between May and September. For the ancient cities, much of the year works. In October and November, pack an umbrella whichever coast you choose.