Mirissa Weather in September
Mirissa in September averages 29°C (84°F) during the day and 25°C (77°F) at night. September is part of the rainy season, so frequent rainfall is typical.
Rainfall in Mirissa in September
Mirissa is in the rainy season in September, with rain on around 11 days and an average of 225 mm (8.9 in). With high rainfall totals spread across the month, individual showers can be very heavy. Waterproof gear is strongly recommended.
Temperature in Mirissa in September
September in Mirissa brings typical temperatures with highs around 29°C (84°F) and lows of 25°C (77°F). This kind of day-to-night contrast is typical for this time of year. With lows around 25°C (77°F), the nights are warm enough that a sheet is usually all you need for bedding.
Sunshine in Mirissa in September
The month experiences a moderate amount of sunlight, with 180 hours of sunshine. This provides a nice balance between sunshine and rain.Our weather planner can help you find worldwide destinations with pleasant weather during this period. July and August typically offer the best weather for Mirissa.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Sri Lanka, check out our Mirissa's climate page.
Mirissa Temperature in September
Min Temperature
25°C (77°F)
Max Temperature
29°C (84°F)
Chance of Rain
37%
Precipitation
225 mm (8.9 in)
Rainy days
11 days
Sunshine
180 hours *
Percentage Sunshine
*
Daily Historical Temperatures
43-year average (1976-2025)
Based on our historical records, temperatures in Mirissa typically stay consistent throughout September, with daily highs averaging around 29°C (84°F). Nights are warm, with lows around 25°C (77°F).
Average temperatures in September
Daily Historical Precipitation
43-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Mirissa in September
Browse day-by-day weather records for Mirissa spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Mirissa historical weather extremes in September
Our historical data for Mirissa spans 2004 to 2025, revealing these weather extremes.
- On September 8, 2018, temperatures climbed to 37°C (99°F), marking the warmest September day on record.
- The coldest September day was on September 6, 2004, with a maximum of 26°C (79°F).
- Mirissa registered its coldest September night on September 3, 2020, with temperatures dropping to 16°C (61°F).
Best Places in Sri Lanka in September
Find out more about the weather in Sri Lanka and which places have the best travel conditions in this month. See all of Sri Lanka in September →
perfect weather
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tolerable
unpleasant
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What to Wear in Mirissa in September
Warm but pleasant conditions in Mirissa in September. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. It's going to pour! Pack a good poncho and prepare for very wet conditions. Sunglasses could come in handy during the sunnier parts of your trip.What To Do in Mirissa in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Sri Lanka, check out our Mirissa's climate page.
See the full Mirissa climate overview or explore weather in Sri Lanka.
