New Delhi: In the December-January period this season, Delhi saw foggy conditions for just 252 hours, which is the lowest since 1991-1992, according to the India Meteorological Department (IMD), PTI reported. The report said that the visibility levels were well below 1000 metres. 


Peak fog formation occurs over north India during the December-January period. 


In December 2021, the national capital witnessed foggy conditions for 75 hours over 22 days. This was the lowest in 40 years. 


The city normally sees 288 hours of fog over 26 days in the month.


So far, Delhi has recorded 175 hours of fog over 23 days compared to the normal of 290 hours over 26 days, senior IMD scientist R K Jenamani said, according to the PTI report. 


The December-January period has seen foggy conditions for just 252 hours over 45 days altogether. Normally, foggy conditions persist for 570 hours over 52 days, the IMD data showed, according to the report. 


Delhi Saw Lowest Foggy Conditions In December-January Since 1991-1992


Jenamani said that Delhi saw lowest foggy conditions in December-January after 1991-1992 in terms of total hours and days. In 1991-1992, Delhi saw such weather for 255 hours over 44 days.


He said that not much fog is predicted in the remaining six days of January as winds will be strong in the coming days, according to the report. 


So far, Delhi has not recorded very dense fog in the December-January period. 


The national capital saw dense fog only on seven days as compared to the normal of 18 days and moderate fog on just 13 days.


When the visibility is below 50 metres, very dense fog formation occurs. Visibility is between 50 and 199 metres in case of “dense” fog, between 200 and 499 metres in case of “moderate” fog, and is between 500 and 999 metres in case of “shallow” fog. 


Delhi Witnessed One Of The Longest Cold Spells This January


The national capital has witnessed one of the longest cold spells this January, despite low fog formation, the report said. 


According to weather experts, this happened due to low clouds or upper-level fog preventing long exposure to sun. 


Delhi has recorded six cold days in January so far, the highest in the month in at least a decade, according to the IMD data.


The national capital has recorded a maximum temperature of less than 17 degrees Celsius on 11 days this month, equalling the number of such days in 2015, Jenamani said. 


He said that eighteen such days were recorded in 2003.