The traditional nine-day heatwave period known as 'Nautapa' is set to grip north India from May 25 to June 2. 'Nautapa', drawn from 'Nau' (nine) and 'tapa' (intense heat), refers to the period when the sun transits through Rohini Nakshatra, traditionally viewed as the year's hottest phase. According to Rajasthani folklores, Nautapa is nature's way of balancing seasons before monsoon.