Climate averages 1991–2020
Dehiwala-Mount Lavinia weather
in December.
A hot, wet month: the 6th warmest and the joint 4th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a hot month in Dehiwala-Mount Lavinia: daytime highs average 29.0°C and nights cool to about 23.3°C. By daytime temperature it is the 6th warmest of the 12 months.
Expect about 174 mm of rain on roughly 17 days, which makes December a wet month (the joint 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 44 min on an average December day.
The nearest other city in this atlas is Colombo (11 km away). In December its highs average 29.2°C, about as warm as Dehiwala-Mount Lavinia, with 164 mm of rain.
Among the 12 cities listed in Sri Lanka, Dehiwala-Mount Lavinia ranks 3rd of 12 for the warmest December highs and 5th of 12 for the driest December (rainfall, lowest first). The mean December high of those 12 cities is 27.8°C; Dehiwala-Mount Lavinia is 1.1°C warmer than that mean.
From December to January, average highs rise by 1.0°C to 29.9°C, and monthly rainfall falls from 174 mm to 60 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Dehiwala-Mount Lavinia climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 29.9°C23.1°C | 23.1°C | 60 | 8.7 | 11.812 h |
| February | 30.8°C23.7°C | 23.7°C | 58 | 8.6 | 11.912 h |
| March | 31.0°C24.5°C | 24.5°C | 75 | 14.9 | 12.112 h |
| April | 30.4°C25.0°C | 25.0°C | 174 | 24.1 | 12.312 h |
| May | 29.2°C25.4°C | 25.4°C | 293 | 29.1 | 12.412 h |
| June | 28.6°C25.1°C | 25.1°C | 256 | 26.6 | 12.513 h |
| July | 28.2°C24.8°C | 24.8°C | 205 | 25.4 | 12.512 h |
| August | 28.1°C24.7°C | 24.7°C | 183 | 24.4 | 12.312 h |
| September | 28.2°C24.5°C | 24.5°C | 232 | 24.3 | 12.212 h |
| October | 28.5°C24.2°C | 24.2°C | 328 | 26.1 | 12.012 h |
| November | 28.7°C23.7°C | 23.7°C | 330 | 23.8 | 11.812 h |
| December, selected | 29.0°C23.3°C | 23.3°C | 174 | 16.5 | 11.712 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Colombo in DecemberSri Lanka · 11 kmHigh 29.2°C · Low 23.2°C · 164 mm rain
- Negombo in DecemberSri Lanka · 41 kmHigh 29.1°C · Low 23.5°C · 137 mm rain
- Galle in DecemberSri Lanka · 96 kmHigh 28.0°C · Low 23.9°C · 148 mm rain
- Kandy in DecemberSri Lanka · 98 kmHigh 25.5°C · Low 19.8°C · 214 mm rain
- Matara in DecemberSri Lanka · 123 kmHigh 28.6°C · Low 23.7°C · 199 mm rain
- Ambalantota in DecemberSri Lanka · 150 kmHigh 28.9°C · Low 23.6°C · 153 mm rain
- Batticaloa in DecemberSri Lanka · 223 kmHigh 27.3°C · Low 23.5°C · 302 mm rain
- Kalmunai in DecemberSri Lanka · 226 kmHigh 27.2°C · Low 24.2°C · 310 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Dehiwala-Mount Lavinia) is explained once on the Dehiwala-Mount Lavinia year overview and on the Sources, method and limits page.