"We expect 15 percent shortfall in the seasonal rains," L.S. Rathore, director general of the India Meteorological Department (IMD) told reporters on Friday.
The IMD considers a 50-year average rainfall of 89 centimetres as the long-period average rainfall. Monsoon rains are considered deficient - a drought in layman's terms - if they fall below 90 percent of the 50-year average.
India's monsoon rains will not be enough to save the country from its first drought in three years, the weather office said on Thursday as it forecast that the El Nino weather pattern should reduce rains again in the second half of the June to September season.
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