IMD Predicts Normal Rainfall for India in August-September

India's monsoon season is expected to see normal rainfall during the second half, despite concerns over El Nino and other unfavorable conditions impacting the weather. The India Meteorological Department (IMD) made this announcement on Monday, stating that although El Nino has not had a significant impact on monsoon performance so far, its influence is likely to be visible in the coming months.

August usually accounts for about 30 percent of the total monsoon season's precipitation, and El Nino is generally associated with weakening monsoon winds and dry weather in India. IMD scientists had earlier warned about the possibility of El Nino affecting the second half of the southwest monsoon.

During a press conference, IMD Director General Mrutyunjay Mohapatra mentioned that the country is expected to experience normal rainfall in August and September, but it is likely to be on the lower side, ranging from 94 percent to 99 percent of the normal (422.8 mm). He also explained that normal rainfall falls between 94 percent and 106 percent of the long-period average (LPA) or the 50-year average.

Rainfall in August is predicted to be below normal (less than 94 percent of LPA). However, the situation is expected to improve comparatively in September, according to the IMD. Normal rainfall is crucial for India's agriculture, with 52 percent of the net cultivated area relying on it. Additionally, it plays a significant role in replenishing reservoirs essential for drinking water and power generation across the country. Rainfed agriculture contributes to about 40 percent of the country's total food production, making it a vital contributor to India's food security and economic stability.

The IMD's predictions indicate that east-central India, east and northeast regions, and most subdivisions along the Himalayas are likely to experience normal to above-normal rainfall in August and September. These areas have received 25 percent less rainfall than usual this season. On the other hand, below-normal rainfall is predicted in most parts of peninsular India and western parts of northwest and central India.

El Nino and the unfavorable phase of the Madden Julian Oscillation (MJO) are the primary reasons for the expected below-normal rainfall in August, according to senior IMD scientist D S Pai. The MJO is a large-scale intraseasonal atmospheric disturbance that affects rainfall patterns.

Pai explained that in July, favorable MJO phases had facilitated the formation of several low-pressure systems over the Bay of Bengal, which had brought good rainfall to central and peninsular India. However, he mentioned that this factor was expected to become unfavorable for at least 10-15 days in August.

On a positive note, the IMD reported that neutral Indian Ocean Dipole (IOD) conditions are currently prevailing over the Indian Ocean. The latest climate model forecast indicates that positive IOD conditions are likely to develop during the remaining part of the monsoon season, which is considered favorable for the monsoon.

India witnessed a significant turnaround in monsoon rains in July, shifting from a nine percent deficit in June to 13 percent excess rainfall in July, according to IMD Director General Mohapatra. However, the east and northeast parts of the country recorded the third-lowest precipitation (280.9 mm) in July since 1901.

The region received an all-time low of 234.8 mm of precipitation in July last year and 249.5 mm in 1903. Conversely, northwest India recorded the highest rainfall in July since 2001, at 258.6 mm. Mohapatra pointed out that the east and northeast regions have been witnessing a decreasing trend in monsoon rains and an increasing trend in mean and minimum temperatures.​

The IMD chief also highlighted that India recorded 1,113 heavy rainfall events and 205 extremely heavy rainfall events in July, the highest in five years. This indicates the significance of preparing for and managing extreme weather events during the monsoon season.