Rainfall/ Precipitation in Colombo, Sri Lanka
- Colombo receives 2404 mm (94.6 in) of rainfall per year, or 200.3 mm (7.9 in) per month.
- On average there are 188 days per year with more than 0.1 mm (0.004 in) of rainfall (precipitation) or 15.7 days with a quantity of rain, sleet, snow etc. per month.
- The driest weather is in January when an average of 62 mm (2.4 in) of rainfall (precipitation) occurs.
- The wettest weather is in May when an average of 382 mm (15 in) of rainfall (precipitation) occurs.
Precipitation Table
| Climate Variable | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 | Average Precipitation mm (in) | 62 (2.44) | 69 (2.7) | 130 (5.1) | 253 (10) | 382 (15) | 186 (7.3) | 125 (4.9) | 114 (4.5) | 236 (9.3) | 369 (14.5) | 310 (12.2) | 168 (6.6) | 2404 (94.6) | |
 | Precipitation Litres/m² (Gallons/ft²) | 62 (1.52) | 69 (1.69) | 130 (3.19) | 253 (6.21) | 382 (9.37) | 186 (4.56) | 125 (3.07) | 114 (2.8) | 236 (5.79) | 369 (9.05) | 310 (7.6) | 168 (4.12) | 2404 (58.96) | |
 | Number of Wet Days (probability of rain on a day) | 8 (26%) | 7 (25%) | 11 (35%) | 18 (60%) | 23 (74%) | 22 (73%) | 15 (48%) | 15 (48%) | 17 (57%) | 21 (68%) | 19 (63%) | 12 (39%) | 188 (51%) |