Autumn season in Tamil is called “இலையுதிர் காலம்”. It occurs between September and October and is one of the six traditional seasons observed in Tamil Nadu.
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 Tamil 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 Celsius, 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 the seasonal fruits in Tamil Nadu with the months“
In the central part of Tamil Nadu, the high temperature is due to the low altitude and distance from the sea. This is the region of climatic variation that exhibits the influence of the coastal and the interior location.
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 be rainy days at the beginning of September, and also there will be bright, hot sunshine. As a result of mild showers, the temperature is down a little bit and paves the way for a 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 the US.
| S.No. | Geographical Locations | Weather Recording Stations | Summer Season (°C) | Winter Season (°C) | Rainy Season (°C) |
|---|---|---|---|---|---|
| 1 | Coastal Regions | Chennai | 40°C | 22°C | 25°C |
| 2 | Interior Plains | Vellore | 42°C | 21°C | 22°C |
| 3 | Inland Regions | Thiruchirappalli | 42°C | 20°C | 23°C |
| 4 | Hilly Regions | Kodaikanal | 11°C | 6°C | 14°C |
| 5 | Plateau | Coimbatore | 32°C | 26°C | 21°C |
Winter Season
Tamil Nadu’s 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 temperature of the state starts increasing in the second week of February and gradually increases in the months of March to June. The part of the summer season is known as Agni Nakshatram (Star of Fire) or Kathiri veyyil.
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, in the 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 system in North India, which draws wind from the Indian Ocean. This results in the formation of the southwest monsoon.
During this Southwest Monsoon 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 meagre rainfall from this monsoon. Rainfall during this season decreases from west to east. Coimbatore plateau receives an average of 50 cm of 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.
| Seasons | Tamil Name | Tamil Month |
|---|---|---|
| Summer (April to August) | Ilavenil Muduvenil | Chitirai, Vaikasi, Aani, Aadi |
| Rainy (August to December) | Khar season, Khulir | Avani, Puratasi, Iypasi, Karthigai |
| Winter (December to April) | Mun Pani, Pin pani | Markhazhi, Thai, Masi and Panguni |
Northeast Monsoon
The northeast monsoon season begins in October and lasts until 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.
| Sl. No | Distribution of Rainfall | Amount of Rainfall | Districts |
|---|---|---|---|
| 1 | Very Low Rainfall | Below 800 mm | Coimbatore, Tiruppur |
| 2 | Low Rainfall | 800 mm – 1000 mm | Namakkal, Karur, Thoothukudi, Erode, Dharmapuri, Madurai, Thiruchirappalli, Perambalur, Krishnagiri |
| 3 | Moderate Rainfall | 1000 mm – 1200 mm | Pudukkottai, Virudhunagar, Sivagangai, Thanjavur, Salem, Ramanathapuram, Dindigul, Theni, Vellore |
| 4 | High Rainfall | 1200 mm – 1400 mm | Tirunelveli, Thiruvannamalai, Kanyakumari |
| 5 | Very High Rainfall | Above 1400 mm | Kancheepuram, Chennai, Villupuram, Thiruvallur, Thiruvarur, Cuddalore, Nagapattinam, Nilgiris |
It makes the wind blow towards the Bay of Bengal from North India. After reaching the Bay of Bengal, the wind gets deflected by the Coriolis force and takes the northeast direction. Hence, it is known as the northeast monsoon. As the northeast monsoon is a part of the 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. Cyclones sometimes disrupt crop cultivation and cause severe damage to life and property.
Please find the summary of the above post in the
| Season | Tamil Name | Months | Climate |
|---|---|---|---|
| Autumn | இலையுதிர் காலம் | September – October | Mild showers, slightly reduced temperature, mix of rain and sunshine; transition to cooler season |
| Winter | குளிர் காலம் | January – February | Cool and dry climate; temperatures range from 15°C to 25°C; mist and frost in hill areas |
| Summer | கோடை காலம் | March – May | Hot and dry; temperatures from 30°C to above 40°C; occasional pre-monsoon showers |
| Southwest Monsoon | தென்மேற்கு பருவமழை | Low rainfall due to the rain shadow effect; moderate rainfall in western and southern regions | Main rainy season; heavy rainfall, cyclones are common; coastal regions receive high rainfall |
| Northeast Monsoon | வடகிழக்கு பருவமழை | October – December | Main rainy season; heavy rainfall, cyclones common; coastal regions receive high rainfall |
References
https://environment.tn.gov.in/assets/report/CCM%20Document.pdf