IMD predicts rainfall for August to fall below normal

IOD refers to the Indian Ocean Dipole, which measures the difference in sea surface temperatures between the western and eastern parts of the Indian Ocean. When the IOD is positive, there is rain over India.

"The Indian Ocean Dipole (IOD) is currently neutral. All models suggest a positive IOD is likely to develop in the coming months," MD chief Mrutyunjay Mohapatra said during the press briefing.

Thus, a positive IOD may bring good rains to India despite adverse El Niño conditions.

While conditions for El Nino have developed, its impact has not been felt so far, he added.

Further, normal to above normal rainfall is expected over most parts of divisions adjacent to the Himalayas and those in the east central Indian and parts of east and northeast India.

However, below normal rainfall is likely over southern India as well as northwest and central India. States including East UP, Bihar, Jharkhand, West Bengal and Kerala have already had deficient rainfall in the month of July.

Meanwhile, the monsoon core zone- which comprises of central India plus parts of Rajasthan, saw very good rainfall activity in month of July.

As per the IMD, India logged 315.9 mm rainfall in July which was 13 percent higher than normal. "All regions except east and northeast recorded excess rain," Mohapatra said.

East and northeast regions recorded third lowest rainfall (280.9 mm) in July since 1901; northwest region got highest rain since 2001.

The rainfall averaged over the country as a whole during second half of the monsoon season (August – September) has however, been predicted to be normal, with a tendency to be on negative side of the normal.

Minimum temperature is 2nd warmest since 1901

India also saw the minimum temperatures rise to become the 2nd warmest in the past over 120 years.

High rains, as per chief Mohapatra, remained the reason for the same.

"There was cloudiness in skies due to heavy rainfall. If the sky is cloudy, then radiation emitted by surface of earth cannot escape through the atmosphere, and gets trapped. Thus cloudy nights are generally warmer," he told Moneycontrol.

Rising rainfall due to global warming

The country witnessed excess rainfall in the month of July, which the IMD chief credited to rising global temperatures.

Over years, global warming has led to an increasing frequency of rainfall in all tropical countries, not just India, he said.

"In addition, this year, there has been four low pressure systems developing over the Bay of Bengal which usually bring heavy rainfall activity, which further caused excess rainfall," he added.