Climate of Sri Lanka
The climate is defined as the state of the atmosphere in a particular place for a long period of time (from one month to many millions of years, but in general — over the last 30 years). Climate is the sum of atmospheric elements, solar radiation, temperature, humidity, cloudiness, precipitation, atmospheric pressure, wind
Due to the location of Sri Lanka between 5°55 '- 9°51' northern latitude and between 79°42' — 81°53 'east longitude
, the climate of the island can be described as tropical and equatorial
The central part of the southern half of the island is mountainous with a mountain height of more than 2.5 km. The main regions of the central mountainous terrain contain many complex topographic features, such as ridges, peaks, plateaus, basins, valleys and slopes. The rest of the island is practically flat, with the exception of a few small hills that rise quite low in the lowlands. These topographic features greatly influence the spatial patterns of winds, seasonal precipitation, temperature, relative humidity and other climatic elements, especially during the monsoon season.
The amount of rainfall in Sri Lanka depends on several factors influencing their origin. Monsoon, convective and expressive rainfall account for the largest proportion of annual precipitation. The average annual precipitation varies from 900 mm in the most arid parts (southeast and north-west) to more than 5000 mm in the wettest parts (western slopes of the central mountainous region).
Regional differences observed in air temperatures over Sri Lanka, mainly depend on the height, rather than on the latitude. The mean monthly temperatures differ slightly depending on the seasonal movement of the Sun, and depend on the precipitation. The average annual temperature in Sri Lanka is manifested mainly by a uniform temperature in the lowlands and a rapidly decreasing temperature in the mountainous terrain. In lowlands, up to a height of 100 m to 150 m, the average annual temperature is almost always between +26.5°C +28.5°C, that is, the annual temperature is about + 27.5 ° C. In the highlands, the temperature falls rapidly with increasing altitude above sea level. The average annual temperature in Nuwara Eliya at an altitude of 1800 m above sea level +15.9° C. The coldest month with respect to the average monthly temperature is January, and the warmest months are April and August.
The average annual temperature ranges from +27°C in coastal lowland areas to +16° C in Nuwara Eliya and in the central highlands (1900 m above sea level). This unique temperature feature is evident both on sunny beaches and in the humid tropical forests of the interior of Sri Lanka, and is a tourist attraction.
Climate and Seasons
The climate of Sri Lanka is dominated by the above-mentioned topographic features of the country and monsoons on a regional scale, as well as the wind movement regime in the south-west and northeast. The 12-month period in Sri Lanka can be characterized by 4 climatic seasons as follows:
The first inter-monsoon season
— March to April
South-West Monsoon Season
— May to September
The second inter-monsoon season
— October to November
Northeast Monsoon Season
— December to February
Each of the four seasons is characterized approximately as follows:
First Inter-monsoon season (March — April)
Warm and uncomfortable conditions, with a thunderstorm, like before the rain, especially in the afternoon or evening. These are typical weather conditions during this season. The distribution of precipitation during this period shows that the entire southwestern part of the island receives up to 250 mm of precipitation up to the upland part, and the areas located on the slopes of the southwest mountains experience precipitation in excess — up to 700 mm (771 mm in Keragala). On the most part of the island the amount of precipitation varies (between 100 and 250 mm), except for the northern part of the country near the peninsula of Jaffna (in Jaffna — 78 mm, Elephants Pass — 83 mm).
South-west monsoon season (May — September)
The windy weather in this monsoon facilitates the transfer of warm air by the man, which reigned during the First Inter-Monsoon season. The southwestern monsoon brings rain at any time of the day, day and night, several times with interruptions (mainly in the south-western part of the country). The amount of precipitation in this season varies from 100 mm to 3000 mm and above. The greatest amount of precipitation falls in the middle mountainous areas on the western slopes (Ginigathena-3267 mm, Watawala — 3252 mm, Norton — 3121 mm). The amount of precipitation decreases rapidly from lower regions to regions with a high altitude (in Nuwara Eliya drops to 853 mm of precipitation). In the southwestern coastal strip, from 1000 mm to 1600 mm of precipitation falls during this 5-month period. Low rates in these same months are recorded in the northern and south-eastern regions.
Second Inter-monsoon season (October-November)
Heavy rains, especially in the afternoon or evening, are typical features of the climate during this season. But unlike the First intermusson season, weather, atmospheric pressure and cyclones during this period are affected by the climate in the Bay of Bengal. In such conditions, the whole country experiences strong winds with a wide spread of rains, sometimes it leads to floods and landslides. The second inter-monsoon season from October to November is the period with the most balanced distribution of rainfall across Sri Lanka. Almost the entire island receives more than 400 mm of precipitation this season, and the South-West coast receives the most rainfall (in the Weweltalawa Estate from 750 mm to 1200 mm, in Yatiyanthota to 1219 mm)
Northeast monsoon season (December — February)
A dry and cold wind blows from Indian land. This helps establish relatively cool, but dry weather in many parts of Sri Lanka. At this time of year, the weather is rather pleasant and comfortable, except for some cool morning hours. At this time in the firmament, as a rule, almost no clouds, which provides the island in the daytime with sunlight and a pleasant cool night. During this period, the highest precipitation rates are recorded in the North, as well as on the eastern slopes of the mountainous part of the country, including the eastern slopes of the Rangala Ridge. The maximum precipitation falls on the Cobonella Estate (1281 mm), and the minimum in the Western coastal zone around Puttalam (in Chillaw
— 177 mm).
The location of Sri Lanka between 5 and 10 degrees of northern latitude gives the country a warm climate, unhurried ocean winds and considerable humidity. The average temperature ranges from a minimum of +15.8 ° C in Nuwara Eliya
in the Central Highlands to a maximum of +29 ° C in Trincomalee
in the Northeast coast
(where the temperature can reach even + 37 ° C). The average annual temperature in the country as a whole ranges from +26°C to +28°C. Day and night, the temperature can drop no more than 4-7 degrees, which is very comfortable.
In front of you graphs of precipitation under the influence of the monsoon winds of the Indian Ocean and the Bay of Bengal are marked by four seasons. The first period from mid-May to October, when the winds prevail in the south-west, the moisture enters the island from the Indian Ocean. When these winds collide with the slopes of the central part of the highlands, they bring down heavy rains on mountain slopes and in the southwestern part of the island. Some of the windward slopes receive up to 250 centimeters of precipitation a month, and on the leeward slopes to the east and north-east there are only small rains. The second season occurs in October and November, in the inter-monsoon months. This season periodically there are squalls, and sometimes tropical cyclones bring cloudy weather with rains to the southwest, northeast, and eastern parts of the island. During the third season (December to March) monsoon winds from the northeast bring moisture from the Bay of Bengal. The north-eastern slopes of the mountains can be flooded with up to 125 centimeters of rain during these months. In another inter-monsoon season (from March to mid-May), variable winds and evening showers occur.
Humidity is usually higher in the southwestern and mountainous regions and depends on seasonal variations in precipitation. In Colombo
, for example, the humidity remains above 70% in the daytime throughout the year, reaching almost 90% during the monsoon season in June. Anuradhapura
experiences 60% humidity in the daytime in March, but 79% in November and December. In the highlands, for example, in Kandy
, during the day, as a rule, the humidity fluctuates between 70% and 79%.
On the graphs below you can see the climatic conditions in some of the major resorts of Sri Lanka
Online forecast for Sri Lanka
Lankarus Lanka Private Limited, 2014