The India Meteorological Department on Wednesday issued extreme heat wave alerts for western Rajasthan, Haryana, Delhi and Chandigarh after temperatures rose across the region. The conditions are very likely to persist over parts of northwest India and Central India till May 27, the department said.

The Met department also warned that an intense heat wave was likely to grip the National Capital Region from May 27 to May 29, IANS reported.

A heat wave is declared when a weather monitoring station records at least 40 degrees Celsius or more in the plains, 37 degrees Celsius or more in coastal regions, and at least 30 degrees Celsius or more in the hills.

Palam sizzled on Wednesday as the mercury level touched 45.2 degrees Celsius while the rest of Delhi and the National Capital Region reeled under near-heat wave conditions, the Hindustan Times reported. “Hot winds from the west, a clear sky and scarcity of moisture in the air are helping the mercury shoot up,” an unidentified scientist with the regional weather forecasting centre in New Delhi told the daily.

Easterly winds might cause mild dust storms in Delhi on Thursday, but it would not have any effect on the maximum temperatures, Mahesh Palawat, the director of private weather forecasting agency Skymet, told IANS.