The arrival of the southwest monsoon in Kerala is likely to be delayed this year, the India Meteorological Department said on Monday.

“The monsoon onset over Kerala is likely to be on June 4 with a model error of 4 days,” the weather department said.

The monsoon rains usually lash Kerala by June 1 and cover the whole country by mid-July. Timely and normal rains are critical for India’s farm output.

The weather department declares the onset of monsoon if 60% of 14 weather stations in Kerala and the Union Territory of Lakshadweep receive 2.5 millimetres or more rain for two consecutive days.

On Monday, India Meteorological Department chief M Mohapatra said that the delay is within a standard deviation of seven days and is unlikely to impact agriculture and overall rainfall in the country.

“There is no one-to-one relationship between the onset date and the total rainfall over the country during the season,” Mohapatra told PTI. “Also, the monsoon arriving early or in late in Kerala doesn’t mean it will cover other parts of the country accordingly. The monsoon is characterised by largescale variabilities and global, regional and local features.”

On April 11, the India Meteorological Department said that the country will get normal rainfall during this year’s monsoon. However, Mohapatra had said that El Nino conditions could hurt rainfall during the second half of the season.

The El Nino phenomenon involves the warming of ocean surface temperatures in the eastern and central Pacific. It typically occurs every few years and has been linked to crop damage, fires and flash floods.