Sri Lanka weather by month depends on which side of the island you’re on. The Department of Meteorology counts four seasons. Its south-west monsoon runs May to September and its north-east monsoon December to February, and an inter-monsoon comes before each, in March to April and October to November (Department of Meteorology). Across the 1991 to 2020 station averages, Galle on the south-west coast is driest from January to March, with 71 mm in February. Trincomalee on the east coast is driest from March to August, with 26 mm in June. Daytime heat peaks in March or April at most stations, and in June on the east coast (WMO climate normals).
Key takeaways
- The two coasts dry out at different times: Galle’s driest month is February, Trincomalee’s June.
- Galle’s wettest months are October and May; Trincomalee’s are November and December.
- The average daily high peaks in March or April at 15 of the 20 Sri Lankan stations. On the east coast it peaks in June, and Trincomalee’s 35.4°C is the highest figure of all.
- Nuwara Eliya is the coolest station, at 16.2°C over the year, and Ratnapura the wettest, with 3,688 mm.
- Rain days say more than totals: Galle has about 6 or 7 a month from January to March, and 17 or 18 in May, September and October.
Sri Lanka weather by month: the rain table
Every number below is a 1991 to 2020 average from the World Meteorological Organization’s station normals, downloaded on 19 October 2026 (WMO climate normals). The outer columns are Galle on the south-west coast, 13 m above sea level, and Trincomalee on the east coast, at 24 m. Between them sits Nuwara Eliya in the hill country, at 1,894 m, with its average daily high added.
| Month | Galle rain | Nuwara Eliya rain, high | Trincomalee rain |
|---|---|---|---|
| Jan | 87 mm | 116 mm, 19.9°C | 152 mm |
| Feb | 71 mm | 73 mm, 21.0°C | 96 mm |
| Mar | 90 mm | 72 mm, 22.3°C | 55 mm |
| Apr | 202 mm | 134 mm, 22.5°C | 48 mm |
| May | 316 mm | 172 mm, 21.5°C | 72 mm |
| Jun | 184 mm | 168 mm, 19.2°C | 26 mm |
| Jul | 173 mm | 155 mm, 18.6°C | 51 mm |
| Aug | 162 mm | 132 mm, 19.0°C | 67 mm |
| Sep | 261 mm | 161 mm, 19.5°C | 113 mm |
| Oct | 345 mm | 247 mm, 19.7°C | 216 mm |
| Nov | 283 mm | 226 mm, 19.8°C | 376 mm |
| Dec | 176 mm | 183 mm, 19.4°C | 339 mm |
| Year | 2,348 mm | 1,838 mm, 20.2°C | 1,609 mm |
Sources for the three columns: Galle, Nuwara Eliya and Trincomalee station files.
Reading the table
Millimetres don’t show how often it rains. What counts as a rain day? In these files, any day with at least 1 mm. Galle has about 6 or 7 of them a month from January to March, and 17 or 18 in May, September and October (WMO, Galle). Trincomalee goes from about 2 in June to about 18 in November (WMO, Trincomalee). We downloaded all 20 Sri Lankan station files and ran the sums ourselves. We measured Galle’s station at about 24 km west of Weligama, where we’re based, in a straight line from the coordinates in its file. The best time to visit depends on your route: on these averages, the driest months are January to March on the south-west coast and March to August on the east. Our best time to visit Sri Lanka page takes up the wider question.
Hottest month, coolest place, wettest place
The hottest month
Is April the hottest month, as one holiday company’s page we compared says? Ranking each station’s months by average daily high, we found March or April on top at 15 of the WMO’s 20 Sri Lankan files, for example Galle, Colombo, Katugastota (Kandy) and Anuradhapura. In contrast, the three east-coast stations, Trincomalee, Batticaloa and Pottuvil, peak in June. Trincomalee’s June average of 35.4°C is the highest monthly high at any of the 20. The two hill stations near Ella, Badulla and Bandarawela, peak in August and May (WMO climate normals). On the west coast, though, the year hardly moves. Colombo’s mean temperature only ranges from 27.2°C in December and January to 28.9°C in May (WMO, Colombo). Five stations compare like this (WMO climate normals):
| Station | Hottest days (average high) | Coolest nights (average low) |
|---|---|---|
| Galle | March, 31.6°C | January, 23.4°C |
| Katugastota (Kandy) | March, 32.0°C | February, 18.7°C |
| Nuwara Eliya | April, 22.5°C | February, 10.2°C |
| Anuradhapura | March, 34.8°C | January, 21.8°C |
| Trincomalee | June, 35.4°C | December, 23.8°C |
The coolest place
Nuwara Eliya is the coolest station in the set. Over the whole year its mean temperature is 16.2°C, and February nights average 10.2°C (WMO, Nuwara Eliya). Next comes Bandarawela, 1,226 m up, at 21.0°C (WMO, Bandarawela).
The wettest and driest places
Ratnapura, an inland station 86 m above sea level, collects 3,688 mm in an average year, the most of the 20, with rain on about 198 days (WMO, Ratnapura). Mannar, in the north-west, gets the least, 947 mm, though its file covers 28 of the 30 years. Hambantota, on the south coast east of Weligama, gets 1,042 mm (WMO climate normals).
The four seasons in Sri Lanka
Sri Lanka’s year has four seasons on the Department of Meteorology’s calendar, named in its December 2023 climate newsletter (Department of Meteorology):
- “First inter monsoon”: March and April.
- “South-west monsoon season”: May to September.
- “Second inter monsoon”: October and November.
- “North-east monsoon”: December to February.
Sri Lanka Tourism’s climate guide gives the same four seasons and months (Sri Lanka Tourism). Some travel pages start the north-east monsoon in October, which the Department’s dates place in the second inter-monsoon. October does open Maha, one of the island’s two cropping seasons. A paper in the Department’s journal (January 2026) defines Maha as the “Second Inter-monsoon from October to November” together with the north-east monsoon months. Yala, the other cropping season (not the national park), runs from March to September (Department of Meteorology). Which coast each season wets, and how the 2026 rains have gone, is the subject of our Sri Lanka monsoon season guide.
What each month means for a trip
The months below also draw on other stations in the same set, such as Colombo, Batticaloa and Pottuvil. Thirty-year averages describe the usual pattern, not your particular week.
January
January is one of the south-west coast’s driest months: Galle averages 87 mm, with rain on about 7 days, and Colombo 80 mm on about 5 (WMO climate normals). The east is still in its monsoon, with 269 mm at Batticaloa and 263 mm at Pottuvil. In the hills, Nuwara Eliya’s nights average 10.4°C, so bring a warm layer (WMO, Nuwara Eliya). Our Sri Lanka in January guide takes it region by region.
February
Galle is at its driest in February: 71 mm, on about 6 rain days. Colombo averages 77 mm (WMO climate normals). Nuwara Eliya is almost as dry as it gets, at 73 mm, but its nights are the year’s coldest, averaging 10.2°C (WMO, Nuwara Eliya). The east coast is drying out, though Pottuvil still averages 137 mm (WMO, Pottuvil).
March
The first inter-monsoon begins in March (Department of Meteorology), yet Galle still averages only 90 mm, on about 7 days. Daytime temperatures peak at Galle, Katugastota and Anuradhapura, and Anuradhapura’s average high reaches 34.8°C (WMO climate normals). Trincomalee, meanwhile, falls to 55 mm, so both coasts sit within their four driest months; Sri Lanka in March explains why the east coast can still wait.
April
April is the turn: Galle’s rain jumps to 202 mm on about 12 days and Colombo’s to 249 mm (WMO climate normals), in what Sri Lanka Tourism calls a transitional season of afternoon thunderstorms (Sri Lanka Tourism). Trincomalee, in contrast, has its second-driest month, at 48 mm, and Nuwara Eliya’s days are at their warmest, averaging 22.5°C (WMO, Nuwara Eliya). Wikivoyage puts the start of Arugam Bay’s surf season in April (Wikivoyage).
May
The south-west monsoon arrives in May (Department of Meteorology). Galle averages 316 mm over about 17 days, its second-wettest month, and inland Ratnapura 468 mm. On the east coast it’s the reverse: Batticaloa gets 52 mm, and Trincomalee 72 mm with average highs of 35.2°C (WMO climate normals). Our Sri Lanka in May guide deals with that changeover.
June
Trincomalee and Pottuvil both have their driest month in June, at 26 mm (on about 2 days) and 14 mm. It is also the east coast’s hottest month, with Trincomalee’s highs averaging 35.4°C. On the other side of the island Galle gets 184 mm on about 17 days, and Nuwara Eliya has rain on about 15 (WMO climate normals). For a June trip, Sri Lanka in June weighs the drier east and north against the wet south-west.
July
July looks much like June: Trincomalee averages 51 mm and Pottuvil 17 mm, against 173 mm at Galle on about 15 days. Anuradhapura, in the Cultural Triangle, gets 24 mm after 15 mm in June (WMO climate normals). Love Sri Lanka links the elephant gathering at Minneriya to the dry season from July to October (Love Sri Lanka). Wikivoyage says Arugam Bay gets busy in July and August, when its waves are at their best (Wikivoyage).
August
Of the five south-west monsoon months, August is the lightest at Galle: 162 mm on about 14 days (WMO, Galle). Pottuvil, on the east coast, averages 19 mm and Anuradhapura 43 mm (WMO climate normals). For the gathering itself, Love Sri Lanka’s pick is August and September (Love Sri Lanka).
September
September is the south-west monsoon’s last month (Department of Meteorology), and one of Galle’s wettest, with 261 mm on about 17 days; Colombo gets 264 mm. In the east, Trincomalee climbs to 113 mm (WMO climate normals). Love Sri Lanka’s surf map says Weligama’s surf season usually runs from the start of September to the close of May (Love Sri Lanka).
October
The second inter-monsoon begins in October (Department of Meteorology). It is the year’s wettest month at Galle (345 mm), Colombo (359 mm), Katugastota near Kandy (303 mm) and Nuwara Eliya (247 mm). Galle sees rain on about 18 days, and Trincomalee rises to 216 mm (WMO climate normals). Sri Lanka in October has the station-by-station detail.
November
November moves the heaviest rain north and east. It is the wettest month at Trincomalee (376 mm on about 18 days), Anuradhapura (281 mm) and Jaffna (437 mm, from 20 years of records), while Galle eases to 283 mm (WMO climate normals). In Arugam Bay, Wikivoyage reports, most hotels and restaurants are closed between November and March (Wikivoyage). November also starts the whale-watching season, which Love Sri Lanka’s page runs through to April (Love Sri Lanka). Our Sri Lanka in November guide ranks the month at all 20 stations.
December
The north-east monsoon starts in December (Department of Meteorology). Batticaloa has its wettest month, at 469 mm, and Trincomalee gets 339 mm on about 15 days. Galle drops to 176 mm on about 11 days, and Nuwara Eliya still sees rain on about 15 (WMO climate normals). Sri Lanka in December adds the month’s holidays and a route.
The sea through the year
Rain averages say nothing about currents. GOV.UK’s travel advice for Sri Lanka names 21 September 2026 as its most recent update; we read it on 19 October 2026, when it was still flagged as current (GOV.UK). Its “Swimming safety” paragraph, quoted whole: “Many beaches in Sri Lanka have dangerous surf or rip tides at certain times of the year. Get advice from your hotel or tour operator before going in the sea.” Beyond that, GOV.UK refers readers to the Royal Life Saving Society, for its advice on keeping safe in the water on holiday (GOV.UK).
Questions about Sri Lanka’s weather
Which month is hottest in Sri Lanka?
That depends on the coast. By average daily high it is March or April at 15 of the 20 WMO stations, and June on the east coast, where Trincomalee reaches 35.4°C (WMO climate normals). In the hills it stays mild: Nuwara Eliya’s highest monthly average high is 22.5°C, in April.
What are the seasons in Sri Lanka?
Four, each tied to the monsoons. On the Department of Meteorology’s list, May to September belongs to the south-west monsoon and December to February to the north-east monsoon. The two inter-monsoons fill March and April, then October and November (Department of Meteorology).
What are the summer months in Sri Lanka?
There isn’t a summer in the European sense, because the lowlands stay warm all year: Colombo’s monthly mean only runs from 27.2°C to 28.9°C (WMO, Colombo). A paper in the Department of Meteorology’s journal does call the May to September south-west monsoon the “summer monsoon”, and the December to February north-east monsoon the “winter monsoon” (Department of Meteorology). Those labels name monsoons, not the hottest weather, which comes in March or April at most stations.
Which month gets the most rain?
October at Galle and Colombo, November at Trincomalee and Jaffna, and December at Batticaloa (WMO climate normals). Over a whole year, Ratnapura is the wettest of the 20 stations.
Plan your route around the weather
We’re a small local team in Weligama planning private road journeys across Sri Lanka, as our contact page puts it. Send your travel dates through the Oura Travel contact page, and we’ll suggest which coast and which hill towns suit them, using the averages on this page.
Every weather figure on this page was recalculated from the WMO station files on 19 October 2026. Averages built from thirty years can’t tell you about one particular week, so look at the Department of Meteorology’s forecast shortly before you travel.
