SeasonMapMirissa weather in December
Sri Lanka
December in Mirissa: sweltering, soaked, with muggy air — fine if you can take 21 rainy days.
#7 of 12 months in Mirissa · #511 of 1383 destinations to visit in December · comfort 78/100 (tier B)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Mirissa in December
Other months in Mirissa
Mirissa's forum calls February close to ideal — fewer crowds, good weather, and prime whale-watching season, which regulars say runs November through April. Sightings aren't guaranteed (recent reports put the odds around 50%), though dolphins show up far more reliably; tours head out around 6:45am, and regulars say the earliest departure gives the calmest seas and the best shot.
Add your own note from Mirissa's card on the map.
Mirissa climate normals — December
| Daytime high | 30°C / 86°F | 🔥 sweltering |
|---|---|---|
| Nighttime low | 24°C / 75°F | |
| Feels like (high) | 36°C / 97°F | |
| Sea temperature | 29°C / 83°F | ♨️ bath-warm |
| Rainfall | 180 mm / 7.1 in | ⛈ soaked |
| Rainy days | 21 days | |
| Humidity | 85% | 💦 very humid |
| Dew point | 24°C / 75°F | |
| Sunshine | 9.7 h/day | |
| Daylight | 11.8 h | |
| Wind | 13 km/h / 8 mph | |
| Air quality (US AQI) | 57 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Mirissa in December
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Peak crowdsSouth coast surf season, Christmas and New Year peak, Year-end break in Sri Lanka(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Mirissa's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherMirissa's weather peaks January–March, best around February.
Best weatherFair weatherToughest weather
What's on in Mirissa in December
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Nature
Blue whale season
1 Nov – 15 AprBook earlyBoats leave the harbour before dawn for the shelf edge an hour or two out, and sightings are close to routine between December and March. Pick an operator that keeps its distance; plenty do not.
- Season
South coast surf season
1 Nov – 15 AprCrowdedThe clean swell is round the corner at Weligama, which is where every board hire and beginner lesson on this stretch happens. Mirissa's own bay is for swimming rather than surfing.
- Holiday
Christmas and New Year peak
20 Dec – 5 JanChristmas & New YearCrowdedBook earlyThe fortnight the beach bars run parties and rooms behind the sand cost triple what they do in November. The whale boats sell out the night before rather than the week before. Source ↗
Nearby, and something's on
Within 300 km of Mirissa — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Mirissa?
Mirissa in December — FAQ
- Is December a good time to visit Mirissa?
- December in Mirissa: sweltering, soaked, with muggy air — fine if you can take 21 rainy days. It ranks #7 of 12 months for Mirissa on SeasonMap's comfort score (78/100).
- What is the weather like in Mirissa in December?
- In December, Mirissa averages a daily high of 29.9°C and a low of 24.1°C, with about 180.1 mm of rain over roughly 21 rainy days.
- What is the air quality in Mirissa in December?
- Mirissa has a mean US Air Quality Index of about 57 in December.
Other months in Mirissa
Compare Mirissa in December
Warmer or cooler than Mirissa in December
Similar destinations in South Asia — December
Within 300 km: Nuwara Eliya's Adam's Peak pilgrimage season around 5 Dec – 10 May, and Colombo's Blue whales off Mirissa around 1 Nov – 15 Apr.