Widespread Heatwave

Context:

India is facing an unusually long series of heatwaves that began in the end of March and scorched north India for most of April.
The India Meteorological Department (IMD) said April was the hottest in northwest India in 122 years. It has also been an unusually hot April with temperatures touching above 40°C in large parts of Bihar, Jharkhand and West Bengal.

The heat wave is considered when the maximum temperature of a station reaches at least 40°C for Plains and at least 30°C for Hilly regions.
If the normal maximum temperature of a station is less than or equal to 40°C, then an increase of 5°C to 6°C from the normal temperature is considered to be heat wave condition.
Further, an increase of 7°C or more from the normal temperature is considered as severe heat wave condition.
If the normal maximum temperature of a station is more than 40°C, then an increase of 4°C to 5°C from the normal temperature is considered to be heat wave condition. Further, an increase of 6°C or more is considered as severe heat wave condition.
Additionally, if the actual maximum temperature remains 45°C or more irrespective of normal maximum temperature, a heat wave is declared.

Because of the heat-trapping effects of global warming, climate extremes such as heatwaves are predicted to become more common.
Extreme rainfall events, as well as extended rainless periods, are projected, according to the Intergovernmental Panel on Climate Change’s predictions.
The lack of rainfall in the northern portions of the country is the main cause of the sweltering heat.
Normally, times of extreme heat are interspersed by brief bouts of rain, but this was not the case in March and April.
Ironically, April witnessed the most intense rainfall since 2018, however it was centred in the south and north-eastern parts of the country.

Source: THE HINDU.