🇱🇰 Weather in Mirissa in September
This is what the weather in Mirissa (Sri Lanka) was like in September in 2017–2026.
Key facts at a glance
Avg. daytime high
28.6 °C
28.3 °C – 29.4 °C
Avg. night-time low
26.1 °C
25.5 °C – 26.8 °C
Avg. rain days in period
25.1
84 % of days · ≥ 1.0 mm
Avg. precipitation in period
233 mm
81.4 mm – 522 mm
Avg. sunshine per day
n/a
Sunshine duration is not available from this data source.
Avg. sea temperature
–
Sea temperature unavailable for today (daily limit).
Extremes: Highest temperature 30.4 °C (28 Sep 2024) · Lowest temperature 24.6 °C (1 Sep 2025) · Avg. daily peak wind 26 km/h
Weather mix of all days
- 13Sunny
- 22Partly cloudy
- 13Cloudy
- 101Light rain
- 150Rain
Summary
- On average 28.6 °C during the day and 26.1 °C at night.
- On average 25.1 rain days (Rain day = at least 1.0 mm of precipitation) with 233 mm of precipitation in total.
- Prevailing: Rain.
- Warmest year: 2024 (avg. 29.4 °C), coolest: 2020 (avg. 28.3 °C).
- Wettest year: 2023 (522 mm), driest: 2022 (81.4 mm).
- Extremes: 30.4 °C on 28 Sep 2024 and 24.6 °C on 1 Sep 2025.
Overall values from all 10 years. How is this calculated?
Charts
Temperatures per year
Average over your travel period
Precipitation & rain days
Year by year
2026
Avg. max29.0°Avg. min26.6°- Rain days
- 29 Rain days
- Precipitation
- 292 mm
- Avg. sunshine per day
- n/a
- Sea temperature
- –
Max 30.0 °C · Min 25.9 °C
2025
Avg. max28.9°Avg. min26.3°- Rain days
- 25 Rain days
- Precipitation
- 180 mm
- Avg. cloud cover
- 74 % cloudy
- Sea temperature
- –
Max 29.8 °C · Min 24.6 °C
2024
Avg. max29.4°Avg. min26.8°- Rain days
- 23 Rain days
- Precipitation
- 92.5 mm
- Avg. cloud cover
- 80 % cloudy
- Sea temperature
- –
Max 30.4 °C · Min 25.7 °C
2023
Avg. max28.6°Avg. min26.3°- Rain days
- 30 Rain days
- Precipitation
- 522 mm
- Avg. cloud cover
- 87 % cloudy
- Sea temperature
- –
Max 29.2 °C · Min 25.7 °C
2022
Avg. max28.4°Avg. min25.7°- Rain days
- 14 Rain days
- Precipitation
- 81.4 mm
- Avg. cloud cover
- 60 % cloudy
- Sea temperature
- –
Max 29.7 °C · Min 25.1 °C
2021
Avg. max28.5°Avg. min26.1°- Rain days
- 30 Rain days
- Precipitation
- 192 mm
- Avg. cloud cover
- 71 % cloudy
- Sea temperature
- –
Max 29.2 °C · Min 25.6 °C
2020
Avg. max28.3°Avg. min25.9°- Rain days
- 30 Rain days
- Precipitation
- 272 mm
- Avg. cloud cover
- 89 % cloudy
- Sea temperature
- –
Max 29.0 °C · Min 24.9 °C
2019
Avg. max28.3°Avg. min25.9°- Rain days
- 29 Rain days
- Precipitation
- 414 mm
- Avg. cloud cover
- 82 % cloudy
- Sea temperature
- –
Max 29.9 °C · Min 24.8 °C
2018
Avg. max28.6°Avg. min25.5°- Rain days
- 18 Rain days
- Precipitation
- 133 mm
- Avg. cloud cover
- 67 % cloudy
- Sea temperature
- –
Max 29.5 °C · Min 24.8 °C
2017
Avg. max28.5°Avg. min25.9°- Rain days
- 23 Rain days
- Precipitation
- 149 mm
- Avg. cloud cover
- 74 % cloudy
- Sea temperature
- –
Max 29.6 °C · Min 25.4 °C
Frequently asked questions
- How warm is it in Mirissa in September?
- Daytime highs averaged 28.6 °C, night-time lows 26.1 °C. The highest value of the past 10 years was 30.4 °C (28 Sep 2024), the lowest 24.6 °C (1 Sep 2025).
- How often does it rain in Mirissa in September?
- On average there were 25.1 rain days (at least 1 mm) with 233 mm of precipitation in total.
Check your exact travel dates
Choose your travel period – we show the weather for exactly those days.
Other destinations in September
Data sources
- Weather data
- Data obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program
Reanalysis (weather model constrained by observations) on a coarse grid of about 50 km. Values represent a large area and can differ from local conditions, especially on islands, coasts and in mountains. No sunshine duration.
Reanalysis (weather model constrained by observations)
Reanalysis values represent a grid cell (approx. 25–50 km) and may differ from local measurements on coasts, islands and in mountains. - Sea temperature
- MUR SST data were provided by JPL under support by NASA MEaSUREs program; accessed via NOAA CoastWatch ERDDAP
Daily multi-scale ultra-high resolution (≈ 1 km) analysis of satellite measurements (infrared, microwave) and in-situ data. Represents the foundation temperature below the daily warm surface layer. (Satellite and in-situ analysis) - Place search
- Natural Earth (public domain) · GeoNames (CC BY 4.0) / OpenStreetMap (ODbL)