For the past one week, India, and especially the northern region of the country, has been reeling under a scorching heatwave. India's weather department has issued a severe heatwave warning as temperatures soar, throwing millions of lives and livelihoods out of gear.

While heatwaves are common in India, especially in May and June, summer began early this year with high temperatures from March itself—average maximum temperatures in the month were the highest in 122 years, said a news report from the BBC.

The India Meteorological Department (IMD) has forecast a gradual rise in maximum temperatures by 2 to 4 degree celsius over most parts of north-western and central India till end of April end with "no large change thereafter".

As per news reports, even Prime Minister of India, Narendra Modi issued a statement  on Wednesday, "Temperatures are rising rapidly in the country, and rising much earlier than usual." 

What is a heatwave?

As per terminology of Indian Meteorological Department (IMD), heatwave is declared when the actual maximum temperature of the station reaches at least 40°C or above in plains and at least 30°C in hills. 

Departure of maximum temperature from normal is 4-5°C or more for the regions where the normal maximum temperature is more than 40.0°C and departure of maximum temperature from normal is 5-6°C for regions where the normal maximum temperature is 40.0°c or less.

How is India affected?

As climate change continues to distort the world’s weather patterns, India will face more, and more intense, heatwaves. 

Between 1981 and 2010, the average high in New Delhi was 39.5º C, around May. This means India’s capital city Delhi began experiencing a heatwave— as the IMD predicted it would—from April 28, when the daily temperature moved towards 44º C, which is 4.5º C plus 39.5º C. 

The IMD had issued a ‘yellow alert’ for Delhi– which means you should keep an eye on the mercury—and also said that the heatwave would persist for a few days more.

The Centre for Science and Environment, a think-tank, says that early heatwaves this year have affected around 15 states in India, including the northern state of Himachal Pradesh, known for its pleasant temperatures. Scientists have attributed the current heatwave to local atmospheric factors. But adding to all that, experts maintain, is global warming.

The heat has also triggered an increase in power demand, leading to outages in many states and fears of a coal shortage.

How to stay safe?

Experts have advised the following things you can do to keep yourself safe from this heatwave.

1. Stay indoors in the middle of the day.  Do not try to venture out in the afternoon when the temperature is at its highest
2. Keep yourself hydrated.  Drink plenty of water and fluids during the day to keep your body temperature in check
3. Avoid driving in the hot weather.  Do not drive, especially two-wheelers in the day, as you can fall victim to the hot air blowing at that time.
4. Wear light-coloured, loose and cotton fabric.