Weather in Colombo in September 2025
Average weather
Average temperature in Colombo in September
Going from a maximum of +30°C during the day to a minimum of +24°C during the night, the temperature in September averages around +29°C.
The average maximum temperature goes up 17% by the end of the month, compared with the beginning of the month, from +28°C to +29°C.
Is Colombo warm or cold in September?
Colombo is typically warm in September.
Maximum temperatures go up compared to the previous month from +29°C to +29°C. The minimum temperature also goes up from +25°C to +25°C.
It’s generally warm, but pack a long-sleeve shirt for evenings.
Take a look at how September is compared to other months in Colombo:
Water temperature in Colombo in September
Water in Colombo in September is Warm. It varies from +27°C to +29°C, with an average of +28°C. This is almost similar to the air temperature, which averages +29°C.
In September, water temperatures are average relative to the rest of the year:
Can you swim in Colombo in September?
Climate in Colombo in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +29°C | +29°C | +29°C | ||||
| Min. temperature | ||||||
| +23°C | +23°C | +22°C | ||||
| Max. temperature | ||||||
| +32°C | +32°C | +34°C | ||||
| Rainfall | ||||||
| 173 mm | 225 mm | 300 mm | ||||
| Wind | ||||||
| 4 m/s | 3 m/s | 2 m/s | ||||
| Avg. water temperature | ||||||
| +27°C | +28°C | +29°C | ||||
| Humidity | ||||||
| 84% | 84% | 84% | ||||
| Air pressure | ||||||
| 1009 HPa | 1009 HPa | 1009 HPa | ||||
| Sunny days | ||||||
| 0 | 0 | 0 | ||||
| Cloudy days | ||||||
| 1 | 1 | 1 | ||||
| Rainy days | ||||||
| 29 | 27 | 24 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as ok as in August. The temperature levels stay the same in the area of +29°C for average maximum temperature during the day. Prepare for more rain. Average rainfall goes from 173 mm to 225 mm. Humidity levels don’t change as the month goes on, averaging around 84%. Winds are calmer in comparison to August, going down from 4 m/s to 3 m/s on average. The amount of sunny days stay about the same, averaging 0 sunny days during the month.
October brings much the same weather, it remains ok.
Wind
The average wind speed is 4 m/s getting up to 6 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Colombo is gradually decreasing during September, going from 5 m/s to 4 m/s over the course of the month.
Rain
How was the weather last September in Colombo?
Climate Change over Years
The climate in Colombo in September has not changed much over the last 43 years.
The average temperature was the lowest in 2000 (+29°C) and the highest in 2020 (+32°C). The driest year was 1980 with only 1662 mm of rainfall, and the wettest year was 2006 with 3008 mm.
FAQ
Is September a good time to visit Colombo?
Can you sunbathe in Colombo in September?
Can you swim in Colombo in September?
Is Colombo rainy in September?
Is it sunny in Colombo in September?
Monthly weather in Colombo
Source of the data
For this page, we’ve looked at the typical weather in Colombo, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.