The climate of Northern India is continental in nature with hot summers and mild winters. There is also a brief rainy season
The Conditions in Summer
The vast land mass of Northern India gets heated up quickly and from the middle of the March to about the middle of the June the temperatures rise on the average 10 F every fortnight and the relative humidity falls correspondingly. The temperatures reach more than 110 F by the middle of May and just before the arrival of monsoon, that is the second week of June, temperatures up to 117 F or more must be expected.
The conditions in Monsoon
Monsoon reaches this area by the end of June and persists up to the middle of September. The general features are warm temperatures, high relative humidity and heavy rainfall. The high relative humidity makes live quite difficult and the j=heat index is typically around 110 F.
The Conditions in Post monsoon
The months of October and November are the post monsoon months with little or no rainfall. The sky is clear, generally, of any cloud and relative humidity is low. The days are quite warm, but the nights are cool. So the diurnal range of temperature is quite high -typically more than 30 F.
The conditions in winter
The winter arrives about the first week of December. Days are sunny and bright with a comfortable temperature of around 70 F at midday but the nights are positively cold. Temperatures up to 40 F are common. There is some rainfall, but the both the intensity and duration are much less than that of the monsoon rainfall.
Fog in the winter months
In recent years, due to pollution and urbanization, a thick blanket of fog covers the area almost every year and cold day conditions are observed. The high temperatures fall more than 20 F below the long term average and visibility is also very low. When visiting this region, fog period must be avoided.
Best Season To Visit Northern India
The best season to visit this area is from December to Mid-February when the highs are generally around 70 F and lows around 50 F. Days are bright and sunny and wind is light. This is the most enjoyable season of the whole year.
In short the climate of Northern India is continental in nature with extremes of temperatures and best avoided in the summer months.