India has received 28 percent excess rainfall in the pre-monsoon season so far, according to the India Meteorological Department (IMD) data. The central region has received the most precipitation, with a 268 percent surplus above the normal. The northwest region has received 18 percent more rainfall, while the peninsular region has received 88 percent excess rain during this period. However, the east and northeast regions recorded a 29 percent rain deficit.
Since April 21-22, large parts of the country, barring the eastern and northeastern parts, have experienced a prolonged wet spell owing to several back-to-back weather systems. As a result, most parts of the country experienced significantly lower-than-normal day temperatures during the period. A senior IMD scientist said that such a long period without heatwaves in April and May is “very rare.” Typically, May sees the highest number of heatwave days in India, and a heatwave is declared if the maximum temperature of a station reaches at least 40 degrees Celsius in the plains, at least 37 degrees Celsius in coastal areas, and at least 30 degrees Celsius in hilly regions, and the departure from normal is at least 4.5 degrees Celsius.
In February, India logged its hottest February since record-keeping began in 1901, and the IMD had predicted above-normal maximum temperatures in most parts of the country and more heatwave days in central, eastern, and northwestern regions from April to June. However, not a single place in India has reported a heatwave since April 21.
In April, the weather office had predicted that India would get normal rainfall during the southwest monsoon season (June to September) despite the evolving El Nino conditions. It is likely to be 96 percent of the long-period average of roughly 87 cm, with an error margin of 5 percent. El Nino is generally associated with the weakening of monsoon winds and dry weather in India. The El Nino conditions this year follow three consecutive La Nina years. La Nina typically brings good rainfall during the monsoon season.
The IMD, however, has emphasized that not all El Nino years are bad monsoon years. There were 15 El Nino years between 1951 and 2022, and six of them logged ‘normal’ to ‘above normal’ monsoon rainfall. Rainfall between 96 percent and 104 percent of a 50-year average of 87 cm is considered ‘normal’. Rainfall less than 90 percent of the long-period average is considered ‘deficient’, between 90 percent and 95 percent is ‘below normal’, between 105 percent and 110 percent is ‘above normal,’ and more than 100 percent is ‘excess’ precipitation.
India received 971.8 mm of rainfall in the monsoon season in 2019, 961.4 mm in 2020, 874.5 mm in 2021, and 924.8 mm in 2022, according to the IMD data. In 2018, the country recorded 804.1 mm of precipitation, 845.9 mm in 2017, 864.4 mm in 2016, and 765.8 mm in 2015.
An early onslaught of heatwaves impacted wheat production in India last year, prompting the country, the world’s second-largest wheat producer, to ban exports of the grain in May. In March this year, the government said the export ban on wheat would continue as long as the country does not feel comfortable with the domestic supplies to meet the food security needs.