Monday's temperature dropped two to three degrees below normal for this time of year in Goa.
According to the India Meteorological Department (IMD), the minimum temperature is likely to remain lower than normal for the next few days in Goa.
The alert came in as a cold wave hit the northern and central parts of the country.
In Panjim, the lowest temperature recorded was 19 degrees Celcius.
A thick blanket of fog covered the entire place.
According to the IMD, this is the coldest January in a decade.
The lowest minimum temperature recorded in Panjim was 14 degrees Celsius, which was on January 3, 1991.
Due to fog, visibility in the capital city was poor till around 10.30 am.
Until last week, the weather in Goa was very cool and pleasant.