Close on the heels of the coldest day yet of the season on Friday, the maximum temperature on Sunday was recorded at 12.6 degree Celsius, 8 degrees Celsius below normal.
The minimum temperature recorded was 8 degrees Celsius (one degree Celsius above normal) even as the day remained mostly foggy with visibility up to 600 metres till 8.30 am, the Met officials said.
Statistics from the Meteorological Department show (see box) the minimum temperature has not dipped much, resulting in colder days and relatively warmer nights.
The Met department officials said, “This is normal.”
“Most of the days it was foggy and at times cloudy. For minimum temperature to come down, clear sky and winds from northern direction are a must. In absence of these two conditions, the night temperature does not come down much,” said IMD Director B P Yadav.
The Met office has predicted “fog in the morning and mainly clear sky” for Monday with maximum temperature likely to rise to 15 degrees Celsius but minimum temperature going down to 7 degrees Celsius.
It is the forecast for Tuesday that should have Delhiites worried.
“Fog in the morning. Partly cloudy sky with possibility of thunder development/light rain towards evening/night,” says the weatherman.
Once it rains and the sky is clear of fog and clouds, the temperature at night will dip, said the Met officials.
Explaining the phenomenon, Met officials said during winter season, weather system known as western disturbances affects day-to-day weather of northwest India, including Delhi and surrounding areas.
This is usually associated with cloudy sky, rise in night temperatures and precipitation on some occasions.
This time, after January 3, dense fog is prevailing over most parts of Indo-Gangetic plains — dense fog and cold day conditions for Delhi — due to favourable conditions of moisture, temperature and winds from north.