Colombo (Sri Lanka) weather in May

May in Colombo: sweltering, soaked, with muggy air — not the time — 29 rainy days.

Updated September 2026 · climate normals from ERA5 reanalysis

Colombo🇱🇰 Sri Lanka · Sri Lanka & the Maldives · City43
  1. 70Jan
  2. 72Feb
  3. 66Mar
  4. 60Apr
  5. 43May
  6. 52Jun
  7. 59Jul
  8. 56Aug
  9. 55Sep
  10. 47Oct
  11. 45Nov
  12. 64Dec

#12 of 12 months in Colombo · #1334 of 1413 destinations to visit in May · comfort 43/100 (tier F)

Days
31°C
Nights
26°C
Wet days
29
Sun
8.6 h
Humidity
86%
Daylight
12 h
Colombo, Sri Lanka
Photo: Thilina Alagiyawanna · Pexels

What May is like in Colombo

The southwest monsoon arrives: the wettest weeks on this coast, and the point at which the east of the island becomes the better plan.

monsoonlow season

confidence: high

Traveller notes on Colombo in May

Notes from nearby Nuwara Eliya (103 km away)

Colombo doesn't have its own notes for May yet — these are about Nuwara Eliya, close enough to share the season.

Nuwara Eliya-forum threads on early May weather describe daytime readings as comfortably cool, typically high teens to low twenties, though a cloudy day can push things down toward fifteen. Regulars call this genuinely one of the more reliably damp stretches locally, real showers or thunderstorms likely on most days rather than the exception. Posters describe the town's reputation for persistently cool, moist conditions as well earned, though May specifically adds a heavier rain pattern on top of the usual chill. Regulars recommend real waterproof layers and proper boots given how muddy trails turn after a system, tea plantation walks especially prone to slick footing. Posters call nights genuinely brisk, typically dropping into single digits, a real jacket essential after dark. Regulars recommend flexible outdoor plans given how unpredictable timing runs. The record: 21.3C days feeling like 24C, 13.8C nights, an extraordinarily high 326.7mm across 29 days and 87 percent humidity.
NuwaraEliyaMayRegular · May · 1 month ago · about Nuwara Eliya · Read more on Tripadvisor ↗

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.
SkiesClearByMidMonthPricesClimbToo · December · 1 month ago · Read more on Tripadvisor ↗
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.
GalleFaceAprilRegular · April · 1 month ago · Read more on Tripadvisor ↗
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.
GalleFaceNovemberRegular · November · 1 month ago · Read more on tripadvisor.com.au ↗
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.
InterMonsoonShowers · March · 1 month ago · Read more on Tripadvisor ↗

Add your own note from Colombo's card on the map.

Colombo climate normals — May

Daytime high31°C / 89°F🔥 sweltering
Nighttime low26°C / 79°F
Feels like (high)38°C / 100°F
Sea temperature30°C / 86°F♨️ bath-warm
Rainfall359 mm / 14.1 in⛈ soaked
Rainy days29 days
Humidity86%💦 very humid
Dew point25°C / 77°F
Sunshine8.6 h/day
Daylight12.4 h
Wind16 km/h / 10 mph
Air quality (US AQI)57🙂 moderate

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Colombo in May

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, school holidays in 2 of the markets that fill it

JFMAMJJASOND

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).

Toughest weatherColombo's weather peaks January–March, best around February.

JFMAMJJASOND

Best weatherFair weatherToughest weather

What's on in Colombo in May

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Festival

    Vesak

    30–31 MayReligious feastClosures

    The Buddha's birth, enlightenment and death marked with paper lanterns outside every house and free food stalls, dansal, set up on the roadsides. Alcohol sales stop and meat comes off many menus for the poya. Source ↗

  • Season

    East coast season

    1 May – 30 Sep · usuallyDry season

    While 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 · usuallyRisk

    The 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.

  • Season

    Wet season

    MonsoonRisk

    29 rainy days and about 359 mm in the month — the real kind of rainy season, not afternoon showers.

    from the climate normals

What's on around the world in May →

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?

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Colombo in May — FAQ

Is May a good time to visit Colombo?
May in Colombo: sweltering, soaked, with muggy air — not the time — 29 rainy days. It ranks #12 of 12 months for Colombo on SeasonMap's comfort score (43/100).
What is the weather like in Colombo in May?
In May, Colombo averages a daily high of 31.4°C and a low of 26.1°C, with about 359.4 mm of rain over roughly 29.4 rainy days.
What is the air quality in Colombo in May?
Colombo has a mean US Air Quality Index of about 57 in May.

Within 300 km: Nuwara Eliya's Adam's Peak pilgrimage season around 5 Dec – 10 May, and Trincomalee's Blue and sperm whale season around 1 May – 15 Oct.