The India Meteorological Department (IMD) has predicted a substantial increase in temperatures in Delhi, with the maximum temperature likely to hit 40°Celsius in the upcoming three days. Despite the rising temperatures, no heatwave conditions are expected.
Meanwhile, an intense heat wave continues to grip vast regions of east India, impacting areas such as West Bengal, Odisha, Jharkhand, and Bihar. According to the IMD, this heat wave, which is the second this month, will persist for another five days. Heatwave conditions have been prevalent in Odisha since April 15 and in the Gangetic West Bengal since April 17.
The IMD has issued warnings of heat wave to severe heat wave conditions in parts of West Bengal, Karnataka, Odisha, Tamil Nadu, Uttar Pradesh, and Jharkhand over the next five days. Furthermore, high humidity levels are expected to exacerbate discomfort in coastal Andhra Pradesh, Tamil Nadu, Puducherry, Karnataka, Goa, Kerala, West Bengal, and Bihar.
Substantially high night temperatures are anticipated in east Madhya Pradesh on April 22 and 23. These high temperatures at night pose a significant risk as the body lacks the opportunity to cool down during the night. Increasing nighttime heat is prevalent in urban areas due to the urban heat island effect, resulting in metro areas being considerably hotter than their surrounding areas.
The IMD defines a heat wave as when the maximum temperature of a weather station reaches at least 40°Celsius in the plains, 37°Celsius in coastal areas, and 30°Celsius in hilly regions, with a departure from normal temperatures of at least 4.5 notches. A severe heat wave is declared when the departure from normal temperature exceeds 6.4 notches.
Amid the current but weakening El Nino conditions, the IMD had previously warned of extreme heat during the April-June period, coinciding with the seven-phase Lok Sabha elections in which around a billion people are expected to vote, raising concerns about vulnerability to heat waves. The first phase of elections took place on April 19, with the second phase scheduled for April 26.
The Meteorological office has predicted four to eight heatwave days in various parts of the country in April, compared to the normal occurrence of one to three days. During the entire April-June period, ten to 20 days of heatwave days are anticipated, as opposed to the usual four to eight days. Madhya Pradesh, Gujarat, Odisha, Andhra Pradesh, Madhya Maharashtra, Vidarbha, Marathwada, Bihar, and Jharkhand are expected to experience a higher number of heatwave days. Some locations may endure over 20 heatwave days.
The intense heat has the potential to strain power grids and lead to water shortages in certain parts of India. Global weather agencies, including the IMD, also anticipate the development of La Nina conditions later this year. El Nino conditions, which involve periodic warming of surface waters in the central Pacific Ocean, are associated with weaker monsoon winds and drier conditions in India. La Nina conditions, the opposite of El Nino, bring abundant rainfall during the monsoon season.
In a mid-April update, the IMD predicted above-normal cumulative rainfall during the 2024 monsoon season due to the expected La Nina conditions, which are likely to prevail by August-September. The monsoon is crucial for India’s agricultural sector, with 52% of the net cultivated area dependent on it. It also plays a vital role in replenishing reservoirs that are essential for drinking water and power generation across the country.
