Update 2022-01-24 (3): On Monday evening (24 January, local time), Istanbul Airport also confirmed that flights would not resume before 4 am on Tuesday (25 January, local time).
Update 2022-01-24 (2): According to media reports, Istanbul Airport plans to resume operations before midnight (local time). The suspension of air traffic until 4 am was announced by Turkish Airlines.
Update 2022-01-24 (1): Until at least 4 am on Tuesday (25 January, local time), air traffic at Istanbul Airport was suspended due to the snowfall. At least 400 flights have already been cancelled.