In April, with the establishment of a low area over Bihar and its neighbourhood, a reversal in the pressure gradient occurs. The gradient over the State, however, continues to be weak. With the advancement of summer, the seasonal low over north India deepens and shifts towards the north-west. The pressure gradient over Andhra Pradesh generally increases. October is a month of transition when the reversal of pressure gradient takes place.
Winds weaken and take a northernly component.
The seasonal low begins to establish itself over the Bay of Bengal and conditions revert to the winter pattern. Pressures thereafter continue to rise till January. Sea-breeze is generally felt over the coastal belt throughout the year, especially during afternoons and evenings. Humidity Humidity is high in the coastal belt throughout the year with an average of 70 to 80 per cent in the morning and it decreases in the afternoon by 10 to 15 per cent in the areas away from the coast. In the interior, the afternoon values are low and the humidity drops sometimes even below 30 per cent.