Colombo (Sri Lanka) weather in August
August in Colombo: sweltering, soaked, with muggy air — a gamble, with 28 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#7 of 12 months in Colombo · #1153 of 1413 destinations to visit in August · comfort 56/100 (tier D)
- Days
- 30°C
- Nights
- 26°C
- Wet days
- 28
- Sun
- 9.6 h
- Humidity
- 86%
- Daylight
- 12 h

What August is like in Colombo
Still wet on this coast, while the surf season is at its best on the east side of the island.
monsoonlow season
confidence: high
Traveller notes on Colombo in August
Notes from nearby Bentota (59 km away)
Colombo doesn't have its own notes for August yet — these are about Bentota, close enough to share the season.
Bentota forum threads describe August as bright and sunny most mornings, with cloud building through the afternoon and a real chance of showers by evening - not an all-day washout, but genuinely wet stretches happen too, and this coast sees frequent rain days through the month. The monsoon's bigger effect here is on the sea rather than the sky: ocean swimming turns unreliable due to rough surf and strong currents, though Bentota's sheltered lagoon and river keep watersports viable even on rough-ocean days. Forum consensus was that this window is still workable for a trip, just with beach plans built around the lagoon rather than open water.
Other months in Colombo
Regulars are specific that early in this month can still carry some of November's unsettled weather, with conditions typically clearing by mid-month - the same window where holiday-season prices also climb, a real trade-off between weather and cost. Our row backs that hot, genuinely wet read, 31C reading as a hot 36C, over 24.3C nights, with a substantial 146.6mm of rain across 16.2 days and humidity at 82 percent. Regulars are consistent this counts among the cooler, less humid stretches of the year here even though Sri Lanka stays humid year-round by most other standards. The sea sits at a warm, swimmable 28.8C regardless of which half of the month a trip lands in. The record: 9.5 hours of sun, a 12.7 kph wind and AQI 74.
Colombo-forum threads on April weather confirm this sits right at the hottest, most humid point of the year, the stretch just before the rains properly arrive, with afternoon temperatures regularly touching mid-30s and humidity climbing alongside it. Posters describe mornings as reliably bright and sunny, showers building through the afternoon and arriving as a brief, heavy downpour rather than an all-day event, more frequent as the month wears on. Regulars are consistent the first half of April runs noticeably more comfortable than the back half, worth front-loading a Colombo stretch of a longer Sri Lanka itinerary if the schedule allows. Light, breathable clothing and frequent water breaks are called essential regardless of which half of the month a trip lands in. The record: 32.3C days feeling like a punishing 39C, 25.7C nights, a notably high 161mm across over 25 days, a 30.6C sea and 82 percent humidity.
Sri Lanka-forum threads on November weather (Colombo specifically among the destinations discussed) confirm it's the rainiest month of the year islandwide, though posters note the second half of the month usually runs better than the first. Coastal, low-lying areas like Colombo stay hot and humid enough that regulars advise against proper waterproof rain gear, an umbrella doing the job better without trapping heat against the skin. Showers, when they arrive, are heavy but limited to a few hours, and by some estimates roughly two-thirds of November days still deliver enough sunshine. Swimming on the open southwest coast is a bad bet this month, seas staying rough until at least mid-December. The record actually runs far wetter than the two-thirds-sunny framing suggests: 30.7C days feeling like a punishing 37C, 24.3C nights, a notably high 400mm across nearly 25 days, 86 percent humidity, a 29.2C sea and 8.1 hours of sun.
March is one of the two sunniest months across Sri Lanka and a good one for the west coast, and the qualification regulars add is about humidity rather than rain: this is a tropical country and it gets very humid. Our row's 31.8C reads as 38C at 77 percent. On rain they describe the inter-monsoon pattern - mostly sunny with showers possible towards the evening that do not last long - which is how 90mm spread across 15.7 precipitation days can still read as a sunny month. North of Colombo runs hot and dry; the south-west gets the occasional shower. The record: 25C nights, 10.5 hours of sun, a 29.2C sea and AQI 111.
Add your own note from Colombo's card on the map.
Colombo climate normals — August
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Colombo in August
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Quietthe editor's quiet month, Esala Perahera, August break in Sri Lanka
Peak crowdsBusyShoulder seasonQuiet
Best months for Colombo's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherColombo's weather peaks January–March, best around February.
Best weatherFair weatherToughest weather
What's on in Colombo in August
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
East coast season
1 May – 30 Sep · usuallyDry seasonWhile this coast is under the monsoon, the other side of the island is in its dry season: Trincomalee, Pasikudah and the surf at Arugam Bay are at their best exactly when Colombo is at its worst.
- Season
Southwest (Yala) monsoon
15 May – 15 Sep · usuallyRiskThe southwest monsoon soaks Colombo and the west and south coasts, with rain in heavy bursts and a sea too rough for the beach towns south of the city. Low season here, high season on the far side of the island.
- Festival
Esala Perahera
18–28 AugReligious feastCrowdedBook earlyTen nights of tusker elephants, whip-crackers, fire dancers and drummers processing through Kandy, three hours inland. Rooms along the route are sold a year ahead and the town is impassable on the last nights. Source ↗
- Season
Wet season
MonsoonRisk28 rainy days and about 227 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
Nearby, and something's on
Within 300 km of Colombo — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Colombo?
Colombo in August — FAQ
- Is August a good time to visit Colombo?
- August in Colombo: sweltering, soaked, with muggy air — a gamble, with 28 rainy days. It ranks #7 of 12 months for Colombo on SeasonMap's comfort score (56/100).
- What is the weather like in Colombo in August?
- In August, Colombo averages a daily high of 30.4°C and a low of 26.3°C, with about 226.6 mm of rain over roughly 27.7 rainy days.
- What is the air quality in Colombo in August?
- Colombo has a mean US Air Quality Index of about 55 in August.
Within 300 km: Sigiriya's The Gathering at Minneriya around 15 Jul – 30 Sep, and Trincomalee's Blue and sperm whale season around 1 May – 15 Oct.