A heatwave could return in northwest India from May 7 and in central India from May 8, the India Meteorological Department said on Thursday.

The heatwave could also return in Rajasthan from May 7 to May 9, and in south Haryana, Delhi southwest Uttar Pradesh, Madhya Pradesh and Maharashtra’s Vidarbha region on May 8 and 9, the weather forecasting agency said.

On Wednesday, some parts of Delhi received a hailstorm and rain, causing the temperatures to cool down in the evening, according to PTI. Some parts of Punjab, Haryana, north Rajasthan, western and central Uttar Pradesh also experienced hailstorms, light rain and strong winds.

Delhi, as well as parts of Haryana and Uttar Pradesh, have been experiencing record temperatures over the past two months. This year, Delhi recorded its second hottest April in 72 years.

The absence of rainfall and thunderstorms had caused high daytime temperatures in north India, India Meteorological Department’s Director General Mrutryunjay Mohapatra had said on April 29.

For the plains, a heatwave is declared when the maximum temperature goes up to 40 degrees Celsius or more and is at least 4.5 degrees above normal. A severe heatwave is when the normal temperature is 6.5 degrees Celsius more than the normal.

Take measures to control heatwave: Modi

Prime Minister Narendra Modi on Thursday held a meeting with officials from the India Meteorological Department and the National Disaster Management Authority on measures to control heatwave in India and preparations for the monsoon.

States and Union Territories were advised to prepare “heat action plans” at state, district and city levels, according to a press release.

The prime minister told officials to make arrangements for monitoring the quality of drinking water during the monsoon.