Tamil Nadu climate
Tamil Nadu lies to the south of the Tropic of Cancer, which is near the Equator. It receives vertical Sun rays and the temperature is relatively high throughout the year.
The east coast of Tami Nadu enjoys a tropical maritime climate and the Bay of Bengal and Indian Ocean influence the climate of the coastal regions.
Tamil Nadu’s climate is relatively hot and its annual temperature ranges from 18 to 43 degrees Celcius and its annual rainfall is about 958.5 mm.
The east coast experiences a tropical maritime climate and the western region has a mountainous climate. The mountainous climate prevails over the Blue Mountains, Anaimalai, and Kodaikanal Hills. These areas have cool and pleasant climates due to thick forests and high altitudes.
Please check Seasonal fruits in Tamil Nadu with months
In the central part of Tamil Nadu, the high temperature is due to the low altitude and distance from the sea. The migration of vertical sun’s rays leads to the formation of different seasons in Tamil Nadu as follows.
Autumn season in Tamil nadu
The Autumn season in Tamil Nadu starts from September to October. There will rainy days at the beginning of September and also there will bright, hot sunshine.
As a result of mild showers, the temperature is down a little bit and paves the way for cooler winter in the coming months.
This is the best time for tourists to visit Tamil Nadu. Tamil Nadu’s autumn may not be like Europe and US.
Winter Season
Tamil Nadu climate during Winter is not the same as Temperate regions like Europe, Northern America, etc, there is no snowfall just a reduction in temperature.
In Tamil Nadu, the winter season comes during January and February. It is due to vertical rays of the Sun falling between the Tropic of Capricorn and the Equator. Thus India and Tamil Nadu receive slanting Sun rays.
There is less difference between Summer and Winter. The weather is slightly cooler and the temperature is not very high. The temperature during the winter varies from 15°C to 25°C.
However, the Hill station in Tamil Nadu experiences below 5°C occasionally, and also some valleys in the Nilgiris recorded even 0°C. This drop in temperature leads to the formation of thick mist and frost and the winter season in Tamil Nadu is practically dry.
Summer Season
The apparent migration of the sun towards the north during March, April, and May result in the reception of vertical sun rays by South India.
Thus Summer season in Tamil Nadu, there is a steady rise in temperature from the equator.
Hence, Tamil Nadu located to the south of the Tropic of Cancer experiences high temperatures.
Generally, the temperature varies from 30°C to more than 40°C.
During this season particularly in the month of May, the southern part of the state receives some rainfall from pre-monsoon showers (Mango/Blossom showers) and some parts experience convectional rainfall.
Southwest Monsoon
The intense heating of the landmass of the north by the sun during March to May creates a well-developed low pressure in North India, which draws wind from the Indian Ocean.
This results in the formation of the southwest monsoon.
During this season, Tamil Nadu is located in the rain shadow region for the wind, which blows from the Arabian Sea. As a result, Tamil Nadu receives only a meager rainfall from this monsoon.
Rainfall during this season decreases from west to east. Coimbatore plateau receives an average of 50 cm rainfall.
However, the southern districts like Kanyakumari, Tirunelveli, and The Nilgiris record 50–100 cm of rainfall during this period.
The rainfall is scanty in the eastern part of the state.
Northeast Monsoon
The northeast monsoon season commences from the month of October and lasts till mid-December. The high pressure created over Central Asia and the northern part of India becomes the source for the northeast monsoon winds.
The apparent migration of the sun from the Tropic of Cancer to the Tropic of Capricorn causes a change in receiving temperature and air pressure during this season.
It makes the wind blow towards the Bay of Bengal from North India. After reaching the Bay of Bengal, the wind gets deflected by Coriolis force and takes the northeast direction.
Hence it is known as the northeast monsoon. As the northeast monsoon is a part of returning southwest monsoon wind, it is also called the retreating monsoon.
This is the main rainy season for Tamil Nadu, accounting for 48% of annual rainfall. Coastal districts of the state get nearly 60% of their annual rainfall and the interior districts get about 40–50% of the annual rainfall during this season.
Tropical cyclones are common during this season. Cyclones originating from the Bay of Bengal bring heavy rainfall to the eastern coastal regions of Tamil Nadu.
More than 50% of the state’s rainfall is received from tropical cyclones during this period and the east coastal region receives 100 to 200 cm of rainfall.
The rainfall received by the central and northwestern parts is 50–100 cm. The cyclones sometimes disturb the cultivation of crops and cause severe damage to life and property.