A Western Disturbance will approach the western Himalayan region, but the system will not be very intense and its affect on the northern plains particularly, in the areas of Punjab, Haryana and Delhi will be minimal.
Now, the temperatures over Northwest and Central India have started rising. The maximum temperatures over South Central Pakistan adjoining Rajasthan and Gujarat are also recording in the mid 40s. Many stations in South Pakistan have already touched 45°C.
Westerly winds will be blowing from the west over Rajasthan and the northern plains. These westerly winds will be travelling from areas where temperatures are already in the 40s. The winds will be hot and dry and will increase the temperatures significantly.
By April 21 or 22, Delhi will also touch 40°C and summer will finally kick in. By the end of April, loo, which is a strong, hot and dry summer afternoon wind, which blows over the Indo Gangetic plains will affect the residents of Delhi.
Image Credit (delhitourismandhotels.com)