Explained: Why Is Northwest India Experiencing More Heatwaves

As India's northwest braces for more heatwave days this summer, capital Delhi has ordered the closure of all schools as temperatures surge as high as 47 degrees Celsius ahead of voting in the final two phases of national elections.

The India Meteorological Department said a confluence of weather patterns was driving up temperatures in the breadbasket region.

WHY IS INDIA SEEING MORE HEATWAVES?

Summer temperatures often peak during May in India, but IMD scientist Soma Sen Roy said the department was predicting 7-10 heatwave days in northwestern regions this month, compared to the usual 2-3 days.

This was largely due to fewer non-monsoon thundershowers and an active but weakening El Nino, she said, referring to a climate pattern that typically leads to hot and dry weather in Asia and heavier rains in parts of the Americas.

Warm, westerly winds blowing in from Pakistan also contributed to the heat, she said.

Other parts of India have already seen summer temperatures climbing to record peaks, including eastern and southern India, where temperatures in April were among the highest on record.

The weather department also declared a rare heatwave in the southwestern coastal state of Kerala last month.

EXTREME HEAT, POLLS

On Sunday, Najafgarh area in southwest Delhi recorded a maximum temperature of 47.8 degrees Celsius (118.04F), the highest this summer.

The IMD threshold for a heatwave is when the maximum temperature reaches 40C in the plains, 30C in hilly areas, 37C in coastal areas and when the departure from the normal maximum temperatures is at least 4.5 degrees.

Delhi will vote on Saturday, along with the nearby states of Haryana and Uttar Pradesh, among others, in the penultimate phase of a seven-phase general election.

The IMD has declared a red-alert for a heatwave this week in Delhi, indicating a likelihood of searing temperatures that could cause heat-related illness for those exposed.

WHAT IS THE WEATHER DEPT FORECASTING?

The IMD has said heatwave to severe-heatwave conditions are very likely this week in many parts of grain-producing states like Punjab, and Haryana in the northwest, along with parts of Delhi and nearby Rajasthan, Madhya Pradesh and Uttar Pradesh.

The meteorological department is also forecasting "extremely" heavy rainfall over the southern state of Kerala this week and in neighbouring Tamil Nadu state, due to cyclonic circulation - referring to a particular wind circulation pattern - over Kerala.

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