Delhi saw foggy conditions — with visibility levels below 1000 meters — for just 252 hours in the December-January period this season, which is the lowest since 1991-92, according to the India Meteorological Department (IMD). The December-January period is known for peak fog formation over north India.
The capital witnessed foggy conditions for 75 hours over 22 days in December 2021, which was the lowest in 40 years.
Normally, the city sees 288 hours of fog over 26 days in the month. In January so far, the city has recorded 175 hours of fog over 23 days as compared to the normal of 290 hours over 26 days, senior IMD scientist RK Jenamani said.
Altogether, the December-January period has seen foggy conditions for just 252 hours over 45 days as against the normal of 570 hours over 52 days, the IMD data showed.
In terms of total hours and days, Delhi saw lowest foggy conditions in the December-January period after 1991-92 when it saw such weather for 255 hours over 44 days, Jenamani said. Not much fog is predicted in the remaining six days of January as winds will be strong in the coming days, he said.
The capital hasn’t recorded very dense fog in the December-January period so far. It saw dense fog only on seven days as compared to the normal of 18 days and moderate fog on just 13 days as against 33 days normally. Very dense fog is when visibility is below 50 meters. In the case of “dense” fog, visibility is between 50 and 199 meters, “moderate” is 200 and 499 meters, and “shallow” is 500 and 999 meters.
Despite the low fog formation, Delhi has witnessed one of the longest cold spells this January. It is due to low clouds or upper-level fog preventing long exposure to sun, weather experts said. According to the IMD data, the capital has recorded six cold days in January so far, the highest in the month in at least a decade.
Jenamani said Delhi has recorded a maximum temperature of less than 17 degrees Celsius on 11 days this month, equalling the number of such days in 2015. Eighteen such days were recorded in 2003, he said.