Climate averages 1991–2020
Dehiwala-Mount Lavinia weather
in May.
A hot, very wet month: the 5th warmest and the 10th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a hot month in Dehiwala-Mount Lavinia: daytime highs average 29.2°C and nights cool to about 25.4°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 293 mm of rain on roughly 29 days, which makes May a very wet month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 26 min on an average May day.
The nearest other city in this atlas is Colombo (11 km away). In May its highs average 29.5°C, about as warm as Dehiwala-Mount Lavinia, with 279 mm of rain.
Among the 12 cities listed in Sri Lanka, Dehiwala-Mount Lavinia ranks 9th of 12 for the warmest May highs and 12th of 12 for the driest May (rainfall, lowest first). The mean May high of those 12 cities is 30.6°C; Dehiwala-Mount Lavinia is 1.4°C cooler than that mean.
From May to June, average highs fall by 0.7°C to 28.6°C, and monthly rainfall falls from 293 mm to 256 mm.
The annual picture
May 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, selected | 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 | 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
May in nearby cities
- Colombo in MaySri Lanka · 11 kmHigh 29.5°C · Low 25.4°C · 279 mm rain
- Negombo in MaySri Lanka · 41 kmHigh 29.6°C · Low 25.7°C · 255 mm rain
- Galle in MaySri Lanka · 96 kmHigh 28.6°C · Low 25.5°C · 279 mm rain
- Kandy in MaySri Lanka · 98 kmHigh 28.0°C · Low 22.0°C · 125 mm rain
- Matara in MaySri Lanka · 123 kmHigh 29.0°C · Low 25.4°C · 224 mm rain
- Ambalantota in MaySri Lanka · 150 kmHigh 31.0°C · Low 25.9°C · 101 mm rain
- Batticaloa in MaySri Lanka · 223 kmHigh 33.4°C · Low 26.2°C · 50 mm rain
- Kalmunai in MaySri Lanka · 226 kmHigh 32.3°C · Low 26.6°C · 59 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.