Tropical, humid, and shaped by two monsoons
Colombo sits at 6.9°N on Sri Lanka’s west coast. Temperatures barely move across the year — expect 25-32°C daily highs regardless of season. Humidity stays high (75-85%), which makes the afternoons feel heavier than the number suggests.
What varies is rain. Colombo is hit by two monsoons: the southwest monsoon from May through September (the heavier one) and a second wet window in November and early December. In between, there are dry windows long enough to plan outdoor work sessions.
| Month | Temp (°C) | Rain Days | Sun hrs/day |
|---|---|---|---|
| Jan | 27° | 10 | 10.5h |
| Feb | 27.4° | 17 | 9.2h |
| Mar | 28.3° | 7 | 11.3h |
| Apr | 27.7° | 26 | 9.4h |
| May | 27.8° | 30 | 9.1h |
| Jun | 27.2° | 29 | 9.8h |
| Jul | 27.2° | 26 | 10h |
| Aug | 26.8° | 25 | 10.3h |
| Sep | 26.9° | 30 | 9.6h |
| Oct | 27° | 22 | 8.5h |
| Nov | 26.5° | 25 | 8.2h |
| Dec | 26.7° | 19 | 10.1h |
Best months for a workation
January and March are the driest months — 7-10 rain days, 10-11 sun hours daily, and the lowest humidity of the year. If you want reliable outdoor cafe sessions and weekend beach trips to the south coast, this is the window.
February is still solid despite a bump to 17 rain days — the showers are usually short afternoon storms that clear quickly. Mornings stay sunny.
May through September is the southwest monsoon. Rain nearly every day, often in heavy bursts. You can still work — just plan for indoor days. Flooding occasionally affects low-lying areas near the Beira Lake and Wellawatte.
October-November sees the second monsoon kicking in. December improves as the dry season returns.
What to pack
- Dry season (Jan-Mar): Lightweight cotton and linen, sunscreen SPF 50, a reusable water bottle. Morning temperatures are pleasant (~24°C) — take advantage.
- Monsoon (May-Sep, Nov): A compact travel umbrella, quick-dry clothing, waterproof laptop sleeve, sandals you do not mind getting wet.
- Year-round: A light long-sleeve for air-conditioned cafes and coworking spaces — they run cold against the outside heat.
Air quality
Colombo’s AQI averages 69 (“moderate”), with PM2.5 around 30 µg/m³. Traffic in Kollupitiya and Bambalapitiya is the main source. Air quality improves noticeably after monsoon rains wash out particulates. Sensitive individuals should consider an N95 mask for rush-hour walks along Galle Road.