2.2   Monsoon · Part 2

direction of wind is from east to west. The rain during this season generally occurs over the Western Himalayas, Tamil Nadu and Kerala. Western disturbances and associated trough in westerlies are main rain-bearing system in northern part of the country. The jet stream plays a dominant role in bringing these disturbances to India. Western disturbances cause rainfall in Punjab, Haryana and Himachal Pradesh, and snowfall in the hills of Jammu and Kashmir. This rainfall is very useful for the cultivation of winter wheat. . Summer Season During this season, rays of the sun fall vertically over the peninsular India. Hence, there is a steady increase in temperature from south to north. It is practically hot and dry in the entire country in the initial part of this season. Weather over the land areas of the country is influenced by thunderstorms associated with rain and sometimes with hail mostly in the middle and later part. During this season, temperature starts increasing all over the country and by April, the interior parts of South India record mean daily temperatures of °C– °C. Central Indian land mass becomes hot with daytime maximum temperature reaching about °C at many locations. Because of the atmospheric pressure conditions, the winds blow from southwest to northeast direction in Arabian Sea and Bay of Bengal. They bring pre-monsoon showers to the west coast during the month of May. There are few thunder showers called “ Mango Showers ” which helps in quick ripening of mangoes along the coast of Kerala and Karnataka. “ Norwesters ” or “ Kalbaisakhis ” are the local storms with thunder that blow from north western part and rain lasting for short durations. It occurs over the eastern and north eastern parts over Bihar, West Bengal and Assam during April and May. . Southwest Monsoon or Rainy Season The southwest monsoon is the most significant feature of the Indian climate. The onset of the southwest monsoon takes place normally over the southern tip of the country by the first week of June, advances along the Konkan coast in early June and covers the whole country