Low visibility conditions can produce major disruption to air traffic. On 24 and 25 Feb 2005, dense fog blanketed the Hong Kong International Airport (HKIA) under the background of a moist maritime airstream. The poor visibility resulted in 23 diversions in the two days. This was more than the total number of diversions due to weather during the whole of 2004.

At the peak of the episode - in the morning of 25 Feb 2005, visibility at HKIA dropped to a minimum of only 200 m. This was the lowest ever observed at HKIA, breaking the previous record (380 m) set on 9 April 1997 before the airport opened.

Fig. 1 Photo taken on 25 February 2005 from the control tower looking towards the southeast. Normally the south runway and taxiways could be seen (see Fig. 2).

Fig. 2 Photo taken on 27 June 2005 from the control tower looking towards the southeast.

Fig. 3 Another photo of HKIA in fog taken on 8 February 2005 looking towards east-southeast where part of the passenger terminal building could be seen on the left.