With a deficient-southwest monsoon in June, July and near normal in August; rains in September — the last month of the four-month season— have assumed critical importance.
In normal years, the intensity of monsoon goes down considerably by September and the month receives just 10-20 per cent of the entire quantum of rain during the season. But, there has been exception to this pattern.
September rains have a strong bearing on rabi sowing, as good rainfall in the later part of the monsoon season leaves the soil with adequate moisture to aid the sowing of rabi crops. It also helps in filling up the reservoirs across the country, crucial for irrigation during the rabi season (October-November to February) in north India, and also for drinking water and electricity generation.
However, during the last big drought of 2009, rainfall in September was better than in August, and this helped in compensating for the loss in crop output during the kharif season (May-June to September-October) with a good rabi harvest.
According to the India Meteorological Department (IMD), September rainfall in 2009 was around 20.2 per cent below normal, a significant improvement from 26.5 per cent below normal in August.
In five out of the last 10 years, September rainfall have been more than in August. There are exceptions, like in 2002 when India suffered a drought.
This year, if IMD and global weather forecasters are to be believed, September rains would be less and their intensity would also go down compared to August rainfall due to the El Nino weather phenomenon that causes less rainfall. If that happens, it could harm the prospect of rabi sowing, which for some crops begins from October-end.
“Till now, we firmly believe that rainfall in September will be less than that of August this year,” said D S Pai, head of Long Range Forecast division of the IMD.
Nevertheless, the strong showing of August rainfall has wiped off much of the drought-like conditions prevailing in northwestern and western parts of the country, barring pockets where the situation is still not out of the woods.
August rains have narrowed down the overall rainfall deficiency for 2012 monsoon season to 14 per cent below normal. The deficiency was over 20 per cent at the beginning of August.
The biggest drop has been in northwest India, where rainfall deficiency fell to 17 per cent from a high of over 50 per cent in July.
Experts believe that if the rainfall maintains its current strong phase for another week or so, then the overall deficiency would come to somewhere around 10 per cent by August-end.
The rains have also helped in improving the water levels in major reservoirs across the country, and according to the Central Water Commission (CWC), the water in the storages is around 57 per cent of full reservoir level (FRL).
In end-June, the levels had dropped to just 16 per cent of the FRL.
The met office said rains would continue to be heavy over east, northwest, western and central parts of the country during the week as well.
