Gorakhpur has been one of the most preferred pockets for intense fog activity. The city starts witnessing shallow fog from mid-November and goes up to reporting very dense fog till January, even extending up to mid-February.
The geographical features of the city makes it vulnerable to fog. Gorakhpur lies in the foothills and has close proximity to huge rivers like Rapti. Also during this time, winds are light and calm in nature. All these factors make it an ideal destination for fog throughout the winter season.
The city reports nil visibility for several days at a stretch. As the thick of winter commences, such conditions will become a regular feature. During the months of December and January, the visibility conditions do not go beyond 1000 meters.
According to Skymet Meteorology Division in India, the reason behind the prolonged foggy condition is that the maximum temperatures fail to rise during this time. As a result fog does not gets dispersed, again creating a conducive atmosphere for fog on the following day. This is how fog becomes a regular feature in Gorakhpur.
The city doesn't gets relief till the time a strong Western Disturbance affects the region and gives rain. However, frequency of such systems are not very high, hence, no big relief is expected for extended duration.