At present, the diurnal variation in temperatures, i.e. the difference between maximum and minimum, is very high in the range of 14 to 15 degree Celsius. Normally, during the month of February and March the diurnal variation remains between 13 and 14 degree Celsius.
Nights are colder while the day becomes warmer. This increased variation makes people vulnerable to several diseases including cough and cold. Due to clear sky and bright sunshine in the day, people tend to become careless and hardly take precaution during early morning and evening hours. People often do not take note of the fact that sudden dip in temperature is witnessed as the sun goes down.
It is true that the diurnal variation is even higher in the month of April but during that time the mornings and nights are also warmer. Therefore, there is not much threat in terms of ailment in April.
The fluctuation in minimum temperatures is also the largest in February. Whenever there is a Western Disturbance or induced cyclonic circulation over Rajasthan, cold northwesterly winds are replaced by warmer southeasterly winds. This condition was witnessed on February 20 when minimum temperature suddenly increased to 20°C in Delhi. On Monday morning, the minimum came down to 11°C and today it witnessed a marginal rise and settled at 12.4°C.
For the next few days, day temperatures in Punjab, Haryana and Delhi will remain in the range of 25 to 27 degree Celsius. Minimums will settle between 8 and 12 degree Celsius. Amritsar could be colder with night temperature around 6°C.
An East-West trough from Madhya Pradesh to East India will develop by February 25, leading to change in wind directions. Minimums could rise once again by then.
Image credit - Telegraph UK