Monsoon rains, crucial for the country's farm-dependent economy, had been 13 percent below normal between June 1 and Sept. 15 and a significant downpour was unlikely in the remaining days of the season, he said.

Nearly 60 percent of India's billion-plus population depend on the farm sector to earn a living and bad rains wipe out their incomes, crucial for industrial growth. Agriculture accounts for 22 percent of the country's gross domestic product.

If the El Nino patterns continued, they might also affect the southwest Indian monsoon in 2005, Rajeevan said.

An El Nino weather pattern, caused by warming of Pacific waters off South America, usually brings stronger or more frequent westerly winds in summer, leading to drought in east coast areas and more rains in the west.

The Australian Bureau of Meteorology said on Wednesday that central Pacific sea temperatures have warmed to a point consistent with an El Nino weather condition. However, the lack of cloud and the eastern Pacific sea temperature were not consistent with an El Nino, it added.

India's weather office had forecast in April that monsoon rains would be 100 percent of the long-period average, with an error margin of five percent.

It said in late June an adverse El Nino effect on this year's monsoon was not expected, though weather officials had said El Nino remained a matter of uncertainty and they were carefully monitoring the developments.

"The El Nino has already developed over the central Pacific region, but it is still not fully blown. It's a moderate El Nino," Rajeevan said, adding that climatic changes over the central Pacific affect the Indian monsoon more due to its proximity with India.

He said normally an El Nino develops over the eastern Pacific region, which has a limited impact on Indian weather.

"The year 2004 has been an eye-opener for us. Probably we should have more studies on the El Nino effect on the Indian monsoon," Rajeevan said.