Seasons In India

In India, there are different types of seasons round the year. The seasons are caused by the tilt of the Earth’s axis of rotation by 23.45 deg from perpendicular to the plan of elliptic. The direction of the rotational axis stays nearly fixed in space during the revolution. Thus the each hemisphere is tipped towards, or away from, the Sun at different times of the year. This creates opposite seasons in the Northern and Southern Hemispheres.

Below picture shows winter in Northern Hemisphere and summer in Southern Hemisphere.

As far as India is concerned, India Meteorological Department ( principal government weather agency ) has defined following meteorological seasons :

1. Winter season :- January & February
Normally dry and fine weather prevails over India during the season. Clear sky, low humidity; low mean temperature with large diurnal temperature range is the normal features of this season. This normal pattern gets disturbed at intervals due to the passage of western disturbances and its associated weather giving systems.

2. Pre-Monsoon season :- March to May
It is a transition season from northeasterly winter circulation to southwest monsoonal circulation. As Sun moves into Northern hemisphere, the land gets heated. Both days and nights are hot. Heat wave conditions over plains of north India, convective activities like sand / dust storms over northwest India and thunderstorms over most parts of the country are the common features of this season.

3. Southwest Monsoon season :- June to September
Monsoon is defined as a seasonally reversing wind system which is characterized by the precipitation. The word monsoon is derived from Arabic word “mausam” which simply means season. Around 75% of annual rainfall is received over most parts of India when winds blowing from southwest direction from Indian ocean into the Indian landmass. Thus the monsoon is known as southwest monsoon. It is a principal rainy season for the country except Jammu and Kashmir and Tamilnadu.

4. Post Monsoon season :- October to December
It is the transition period from summer circulation to the winter circulation. It is also known as retreating monsoon season as monsoon is in withdrawing phase. The main feature of the season is replacement of southwesterly flow of southwest monsoon season by the northeasterly flow across the south peninsula giving maximum rainfall over coastal Andhra Pradesh, Tamilnadu. This season is also called as “Storm Season”, as maximum number of storms form in this season.