The day temperature in Delhi was recorded at 42 deg C, six degrees above normal, while the minimum stood at 31.6 deg C, four degrees above normal.
The Weather office predicted that the monsoon is likely to touch capital in the second half of next week.
Three persons died due to the intense heat wave condition in Uttar Pradesh's Prabudh Nagar district.
The plains of Punjab and Haryana witnessed day temperature above the 40-degrees mark. Narnaul was hottest in Haryana at 43 deg C, four notches above normal, whereas Amritsar was hottest in Punjab with a high of 41.8 deg C, four notches above normal.
Among other places, Rohtak recorded 42.3 deg C, four notches above normal followed by Hisar at 42.2 deg C, two notches above normal.
While Bhiwani had a high of 41.4 deg C, followed by Chandigarh at 41.1 deg C, Ludhiana 40 deg C, Ambala 39.6 deg C and Patiala 39.5 deg C.
The Punjab government has extended the summer vacation in primary schools of the state for another one week.
In Rajasthan, Churu was the hottest place at 44.1 deg C. Other parts of the state like Sriganganagar, Bikaner and Jaipur recorded 42.2 deg C, 41.5 deg C and 41.1 deg C, respectively.
