Quick answer
Sri Lanka is divided by rainfall into three main climate zones. The wet zone, in the southwest quarter, receives more than roughly 2,500 mm a year and takes the southwest monsoon. The dry zone, covering the north, east, southeast and northwest, receives less than roughly 1,750 mm, mostly from October to January. The intermediate zone lies between them. Altitude adds a second layer: hot lowlands, warm mid-country around Kandy and cool up-country around Nuwara Eliya.
Key takeaways
- The wet zone, in the southwest, gets more than roughly 2,500 mm of rain a year.
- The dry zone, covering most of the north and east, gets less than roughly 1,750 mm.
- The intermediate zone lies between them, around Kandy, Kurunegala and Badulla.
- Altitude creates lowland, mid-country and up-country belts with very different temperatures.
- The zones explain why one region is in season while another is wet.
Why a small island has such different weather
Two things shape Sri Lanka's climate: the monsoon winds and the central mountains. The southwest monsoon carries moisture from the Indian Ocean from May to September and drops most of it on the southwest quarter as it rises over the hills. The northeast monsoon brings a smaller amount from the Bay of Bengal from November to January, falling mostly on the east and north.
The southwest gets both its own monsoon and a share of the inter-monsoon storms, so it is wet all year. The rest of the island relies mainly on the end-of-year rain and is dry for much of the summer. The mountains add their own rainfall and cooler temperatures.
The wet zone
The wet zone covers the southwest quarter of the island: the west coast from about Negombo south, the south coast to around Tangalle, the inland districts of Kalutara, Ratnapura and Galle, and the western half of the hills. It receives more than roughly 2,500 mm a year, and parts of the Sinharaja and Ratnapura area get 4,000 to 5,000 mm.
The wet zone is green all year, with rainforest, rubber, tea and dense villages. It is driest from December to March and wettest from May to June and October to November.
- →Includes: Colombo, Galle, Mirissa, Ratnapura, Sinharaja, Nuwara Eliya.
- →Rain: more than roughly 2,500 mm a year.
- →Driest: December to March.
The dry zone
The dry zone covers about two thirds of the island: the north, the east coast, the plains of the Cultural Triangle, the northwest and the southeast around Yala and Hambantota. It receives less than roughly 1,750 mm a year, most of it from October to January. The driest corners, around Mannar and Hambantota, sometimes called the arid zone, get roughly 900 to 1,100 mm.
The dry zone has scrub jungle, open grassland, tanks and paddy, and most of Sri Lanka's national parks. It is the home of the ancient kingdoms, which built tanks to store the rain.
- →Includes: Anuradhapura, Sigiriya, Trincomalee, Jaffna, Arugam Bay, Yala.
- →Rain: less than roughly 1,750 mm a year.
- →Driest: roughly May to September.
The intermediate zone
Between the two lies the intermediate zone, with roughly 1,750 to 2,500 mm a year. It includes Kandy, Matale, Kurunegala, the eastern hills around Badulla and Ella, and a belt around the edges of the wet zone. It gets some rain from both monsoons and from the inter-monsoon storms.
For travellers, the intermediate zone is the in-between: never as wet as Galle in June, never as dry as Anuradhapura in August.
Lowlands, mid-country and up-country
Altitude adds a second set of zones. The lowlands, below about 300 m, cover most of the island and are hot all year, around 29 to 33 °C by day. The mid-country, from about 300 to 900 m, including Kandy, is warm, around 27 to 30 °C. The up-country, above about 900 m, including Ella, Haputale and Nuwara Eliya, is mild to cool, with Nuwara Eliya around 18 to 21 °C by day.
A trip that crosses the zones needs both beach clothes and a warm layer. Lankan Stays & Trails plans routes that follow the zone in season for each trip's dates.
- →Lowlands: hot all year.
- →Mid-country: warm.
- →Up-country: mild days, cool nights.
Frequently asked questions
What are the climate zones of Sri Lanka?
Sri Lanka has three main rainfall zones: the wet zone in the southwest, with more than roughly 2,500 mm a year; the dry zone across the north, east and southeast, with less than roughly 1,750 mm; and the intermediate zone between them. Altitude adds lowland, mid-country and up-country belts.
Where is the wet zone in Sri Lanka?
The wet zone covers the southwest quarter of the island: the west coast from about Negombo south, the south coast to around Tangalle, Ratnapura, the Sinharaja rainforest and the western hills, including Nuwara Eliya. It is wettest from May to June and October to November.
Where is the dry zone in Sri Lanka?
The dry zone covers about two thirds of the island: the north, the east coast, the Cultural Triangle plains, the northwest and the southeast around Yala and Hambantota. It receives most of its rain from October to January and is dry for much of the summer.
Why is the southwest of Sri Lanka so wet?
The southwest faces the southwest monsoon, which carries moisture from the Indian Ocean from May to September and drops it as it rises over the central mountains. The southwest also gets heavy inter-monsoon storms in April and October to November, so it is wet for much of the year.
Which climate zone is Kandy in?
Kandy is in the intermediate zone and the mid-country altitude belt, at about 500 m. It receives roughly 1,800 to 2,000 mm a year from both monsoons and the inter-monsoon storms, and has warm days of about 27 to 30 °C.
How do the climate zones affect travel?
They explain why one region is in season while another is wet. The wet zone's beaches are best from December to April, the dry zone's east coast from April to September, and the Cultural Triangle works most of the year. Routes work best when they follow the zone in season.
How does Lankan Stays & Trails use the climate zones?
Every route is planned to follow the zone in season for the trip's dates: the wet zone's south coast in winter, the dry zone's east coast in summer, and the Cultural Triangle and hills timed to the clearest days. Guests are told what to pack for each belt.