The best time to be in Delhi is between November and March. November heralds the setting in of winter and lasts till mid February. The proximity to the Himalayan mountain range in the North sends cold waves that lower temperatures across Delhi. Winter season peaks in January with nights getting extremely chilly. The weather is cool and sunny during the day. Though winter rains are negligible, Delhi is prone to impenetrable fog (which is more smog these days due to the pollution) in January when the city faces issues of visibility disrupting road, rail and air traffic. February and March bring forth the blossoms making Delhi a potpourri of vibrant colours and hues. This is the most appropriate time for some outdoor tourism since the moderate weather does not get in the way.
Summers in Delhi start from April with temperatures beginning to touch about 38 degree Celsius by the end of the month. The temperatures continue to rise and reach an intolerable 45 degree Celsius by end May. The heat in the months of May and June are unbearable and walking on the melting roads during the daytime becomes an ordeal. Hot winds, called ‘loo' flowing in from the neighbouring Thar Desert in the state of Rajasthan suffocate city life. Protection is required from the heat and the strong winds, since sunstrokes can prove to be fatal. With the sun rising between 5 to 6 am and setting between 7 to 8 pm, Delhi has nearly fourteen hours of daylight! Nights in summers are comparatively comfortable due to the warm winds.
The heat is interrupted by a pleasant break provided by the monsoons. Monsoons, a typical sub continental weather season starts from July and lasts till September in Delhi. Typically the monsoon winds touch Delhi by June 29 every year. Delhi experiences an average annual rainfall of 670 millimetres or 27 inches, most of which falls mostly in the months of July and August. The importance of Delhi's monsoons, locally known as sawan, can be gauged by the fact that the they have motivated hundreds of folk songs and given rise to quite a few classic musical compositions like Megh Malhar, Mian ki Malhar. The parched earth becomes slushy and the tree leaves spring back to life bringing greenery back to the city. Monsoons are an enervating welcome break from the scorching heat although it is difficult to say which is better - the humidity or the heat.