A cold wave is a weather phenomenon characterized by a rapid, significant drop in temperature over a 24-hour period, bringing unusually cold air to a region for several days.

What is the criterion?

• Cold Wave is considered when the minimum temperature of a station drops to 10°C or less for plains and 0°C or less for Hilly regions.
• It can be classified as a severe cold wave when the departure from normal is -6.4°C or less.

What needs to be known about a cold wave?

• The northwesterly winds blowing during the December to February months are the cold winds from the Himalayas, which allow the prevailing cold conditions to continue and intensify.
• The months from January to February are the wintertime in almost all of India, and chances of cold wave development is very much present.
• Punjab, Haryana, Delhi, UP, Rajasthan, Sikkim, Assam, Madhya Pradesh, West Bengal, Bihar, Gujarat, Jharkhand, Odisha, Tripura, Chhattisgarh, Maharashtra, Telangana, Andhra Pradesh, Karnataka, Tamil Nadu are the cold wave-prone states in India.

Source: Down To Earth