Variation Of July Month Rainfall Over India

For a country like India, where rainfall is seasonal in nature, agriculture often becomes tuned with rainy season (June-September). This season is very vital as 66 per cent of the country's cultivable area depends on these rains. Out of 4 months, July rainfall is critical for agronomic activities & hence, if these rains fail the production & yield suffers. So, it becomes essential to understand the nature of July rains over All India & 36 Meteorological Subdivisions (MS) during 1901-2004. It reveals that East & West Madhya Pradesh, East Rajasthan and Saurashtra MSs have 60% or more probability of July deficit. The probability of July & seasonal rainfall deficit is more or equal to 50% over the regions- East & West Madhya Pradesh, West Uttar Pradesh, Saurashtra, Madhya Maharashtra, Uttaranchal and Himachal Pradesh. Upper Air Circulations, Oscillation of Monsoon trough, Western Disturbances & tracks of cyclones forming over the Head bay are synoptic conditions responsible for deficit rains over the North Indian MS. While for the regions covering Madhya Maharashtra & North Interior Karnataka the position of the ridge is the dominant factor in deciding July and seasonal deficit rains.