| Average climate data for Deniyaya, Sri Lanka | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°C) | 29 | 31 | 31 | 30 | 28 | 27 | 27 | 28 | 27 | 28 | 28 | 28 | 31 |
| Average minimum temperature (°C) | 19 | 19 | 20 | 21 | 22 | 22 | 21 | 21 | 21 | 21 | 21 | 20 | 19 |
| Average precipitation (mm) | 85 | 109 | 135 | 249 | 273 | 173 | 163 | 183 | 176 | 359 | 309 | 209 | 2,422 |
| Average rainfall days (days) | 19 | 20 | 26 | 29 | 30 | 28 | 29 | 29 | 26 | 28 | 28 | 26 | 317 |
| Average relative humidity (%) | 79 | 79 | 81 | 85 | 87 | 87 | 85 | 87 | 86 | 87 | 85 | 86 | 84 |
| Average wind speed (km/h) | 4 | 4 | 4 | 4 | 7 | 9 | 9 | 9 | 7 | 6 | 4 | 4 | 6 |
| Average daily daylight hours (h) | 11 | 11 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 11 | 11 | 12 |
| Average daily sunshine hours (h) | 8 | 8 | 8 | 8 | 7 | 7 | 7 | 6 | 7 | 7 | 6 | 6 | 7 |
| Average cloud coverage (%) | 32 | 36 | 37 | 49 | 61 | 64 | 60 | 64 | 58 | 53 | 50 | 48 | 51 |
| Average UV index | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 5 | 5 | 6 | 6 | 6 |
The warmest month, with the highest average maximum temperature, is March (31.2 °C). The month with the lowest average maximum temperature is July (27.2 °C). Overall, the average maximum temperature over the whole year is 28.7 °C.
The month with the highest average minimum temperature is May (21.9 °C). The coldest month, with the lowest average minimum temperature, is February (18.7 °C). Overall, the average minimum temperature over the whole year is 20.5 °C.
The wettest month, with the highest amount of precipitation, is October (358.9 mm). The driest month, with the least amount of precipitation, is January (84.6 mm). Over the whole year there are 2,421.7 mm of rainfall on average.
The month with the most days of rain is May (29.8 days). The month with the fewest days of rain is January (18.9 days). Over the whole year there are 317.4 days of rain on average.
The month with the highest average relative humidity is October (86.9 %). The month with the lowest average relative humidity is January (78.8 %). The overall average relative humidity over the whole year is 84.5 %.
The windiest month, with the highest average wind speed, is June (8.8 km/h). The calmest month, with the lowest average wind speed, is February (3.8 km/h). The overall average wind speed over the whole year is 5.9 km/h.
The month with the cloudiest skies, so the highest cloud coverage, is June (64.4 %). The month with the clearest skies, so the lowest cloud coverage, is January (31.9 %). Over the whole year there is an average cloud coverage of 51 %.
The months with the longest days, so the most daylight, are June and July (Average daylight: 12 h). The months with the shortest days, so the least daylight, are January, February, November and December (Average daylight: 11.1 h). Over the whole year there are 11.7 h of daylight per day on average.
The month with the most sunshine per day is April (Average sunshine: 8.1 h). The month with the least sunshine per day is November (Average sunshine: 5.9 h). Over the whole year there are 7.1 h of sunlight per day on average.
The months with the highest average UV index are January, February, March, April, May, June, July, August, November and December (UV index: 6). The months with the lowest average UV index are September and October (UV index: 5). Over the whole year the average UV index is 5.8.
