As the temperature fell below a record 4 degrees Celsius for the first time this winter on Sunday, December 19, the India Meteorological Department (IMD) issued a ‘yellow alert’ for the residents of Delhi for both Sunday and Monday. A similar alert has also been issued for Uttarakhand till December 21, with many parts of North India witnessing temperatures below the freezing point. For instance, the mercury dipped to -2.5 degrees Celsius in Rajasthan’s Sikar, -2.6 degrees in Churu district, and -0.5 degrees in Amritsar.

Also Read: At 6 degrees Celsius, Delhi shivers – the coldest day of the season so far

What do we understand by a yellow alert?

A cold wave is declared if the maximum temperature falls either 4.5 degrees or 4 degrees below normal. The IMD uses various colour shades to describe the temperature at a place after a close analysis of the weather trajectory over a few days.

According to a report by The Hindustan Times, ‘yellow’ in this chart depicts severely bad weather and serves as a warning that it could get worse in the future – even hampering daily activities. The yellow alert asks residents to be vigilant and take proper care and precaution.

Also Read: Anjeer milk – Recipe and health benefits of this winter drink

The IMD has attributed part of the cold wave in Delhi to the strong northwesterly cold wind, which is expected to be contained from 21 December. The temperature is expected to hover around 19 degrees Celsius during the day on Monday.

DS Pai, head of climate research at the Met department’s Pune office, told the Hindustan Times, “Very cold and dry northerly winds are blowing over the entire northwestern region, which is bringing down both night and day temperatures. This may abate after December 22.”

The Director-General of Meteorology at IMD, RK Jenamani, explained that the wind speed was around 30-40 kmph on Saturday and is expected to fall on Monday, which will hopefully improve the weather condition. He further warned of probable drizzling in the capital on 24 and 25 December.