Colombo Weather in September
Sri Lanka · Tropical climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Colombo sees average temperatures ranging from a low of 24.7°C (76.5°F) to a high of 28.5°C (83.3°F), with a mean of 26.5°C (79.7°F). Compared to the annual average of 26.7°C (80.1°F), this month is 0.2°C cooler than the yearly norm. Precipitation averages 341.1mm, making it approximately 92.0mm wetter than the monthly average of 249.0mm. The city receives an average of 8.6 hours of sunshine per day during September, with relative humidity averaging 86.1%. Wind speeds reach an average maximum of 19.3 km/h. For travelers, this month offers a temperature experience in Colombo, with wetter-than-average conditions compared to the rest of the year.
Colombo's tropical climate is warm and humid year-round, with two monsoon seasons. I've tracked the rainfall patterns and found that the city receives most of its rain from May to August and October to January. The best time for visiting is January to April, when the weather is drier and the coastal attractions are most enjoyable.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 26.7°C (80.1°F) | 26.5°C (79.7°F) | 26.2°C (79.2°F) |
| Rainfall | 256.6mm | 341.1mm | 365.1mm |
| Sunshine | 9.6 hrs | 8.6 hrs | 8.4 hrs |
| Humidity | 85.2% | 86.1% | 86.9% |
| Wind | 19.6 km/h | 19.3 km/h | 17.2 km/h |
| Rainy Days | 30.2 | 30.0 | 30.8 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Colombo in September, the data indicates mixed conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Colombo in September?
The average temperature in Colombo during September ranges from 24.7°C (76.5°F) to 28.5°C (83.3°F), with a mean of 26.5°C (79.7°F).
How much does it rain in Colombo in September?
Colombo receives an average of 341.1mm of precipitation in September, spread across approximately 30.0 rainy days.
What should I pack for Colombo in September?
Based on September weather data, pack lightweight, breathable clothing, sunscreen, and a hat. Rain gear is essential — this month averages 341.1mm of precipitation.
Is September a good time to visit Colombo?
September is a month with challenging conditions. Plan activities carefully and stay hydrated.
Other Months for Colombo
Cities with Similar September Climate (Tropical)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 6.93°, 79.85°. Timezone: Asia/Colombo. Last updated: 2026-07-30.