Hot in Sep
31°C average high
avg high · 19° at night
25°C+ on almost every day
Sri Lanka
Sri Lanka (Colombo) weather in September
Is it warm? Yes. September in Sri Lanka (Colombo) is hot: afternoons average 29°C and nights 25°C. Most days (80%) peak between 27°C and 29°C.
Hot · average high
29°C
25°C or more on almost every day.
- Average low25°overnight
- Sea29°average, 2023–2025
- Rainy days25281 mm in the month
- SkyMostly cloudy83% cloud · 0% clear days
How warm it really gets
Every September afternoon from 2011–2025: 450 days. Most (80%) peaked between 27° and 29°.
September, year by year
The average September high in each year. The warmest, 2024, averaged 29°C; the coolest, 2020, 28°C.
Compared with home
Average September highs. Expect rain on about 25 days (281 mm in a typical month).
- Sri Lanka (Colombo)29°
- London19°
- Manchester17°
- Dublin17°
- Cork17°
- Belfast16°
- Glasgow16°
Warmer in September, not much further
Flying times are estimates from Dublin; Sri Lanka (Colombo) is about 11h 45m.
Hot in Sep
33°C average high
avg high · 18° at night
25°C+ on almost every day · often 35°C+
Hot in Sep
32°C average high
avg high · 20° at night
25°C+ on almost every day
Air: ERA5 reanalysis via Open-Meteo, 2011–2025. Sea: Copernicus Marine analysis via Open-Meteo, 2023–2025. Rainy day = 2 mm or more. Clear day = average cloud cover of 30% or less. These are averages of past weather, not a forecast. Methodology