India can be affected by
tropical cyclones. They are more common in the Bay of Bengal than in the Arabian Sea, but they are also possible in the latter. In southern India, cyclones can penetrate inland and pass from coast to coast; for this reason, Tamil Nadu and southern Andhra Pradesh, which can be directly hit by cyclones from the east, are more at risk than Kerala and Karnataka. In the east, cyclones may penetrate for a few hundred kilometers along a trajectory that goes from the south-east to the north-west; in the north-west, they may affect the coast of Gujarat. The map shows the areas that have been hit by cyclones in the past, so it's just an indication: nothing prevents them from following a different trajectory, although it is unlikely.
In the states crossed by the Himalayas, especially the central-eastern ones, the remnants of cyclones can cause heavy rainfall in the plains as well as snowfall in the highest mountains.
Cyclones generally occur from
April to December, with two intensity peaks before and after the monsoon (in May and October-November).
The
area most at risk is the northern part of the Bay of Bengal (see the coastal stretch in orange in the map). Here, we find the huge Ganges-Brahmaputra delta, shared with Bangladesh, where there is water everywhere and the mainland is flat and located at sea level (see Kolkata), and besides, to the southwest of the delta, the state of Odisha and the north of Andhra Pradesh (see Visakhapatnam, Coringa, Yanam, Machilipatnam). In this area, the strongest cyclones occurred from late April to early June, and in the October-November period.
Generally, the
monsoon inhibits the formation of cyclones, and for this reason, when the monsoon is in full activity, i.e. from July to September, normally cyclones do not form in the south and on the Arabian Sea, and at most, some weak or moderate ones form in the northern part of the Bay of Bengal.
In
December, when cooler air circulates in the center-north, some cyclones, generally not intense, but capable of bringing abundant rainfall, can still occur in the south and in the islands. Very rarely, as in 1981, 1990 and 2021, they can go up towards the northern part of the Bay of Bengal, as it normally happens until November.
Normally, the
far south of India (Kerala, central-southern Tamil Nadu) is directly hit by cyclones only in November and December. In May, a cyclone can occasionally form off the southwest coast, on the Lakshadweep Islands, which can bring heavy rains to Kerala before moving north, and the same thing can happen on the southeastern coast, off the coast of Tamil Nadu.