Hongkongers woke up to a dry and hazy Sunday with multiple districts enduring serious air pollution under the influence of a dusty airstream from the north, and conditions are expected to remain the same for the next few days.

The Observatory said the city experienced its driest April morning since the automatic weather station was set up in 1984, with relative humidity falling to as low as 21 per cent.

The Environmental Protection Department said visibility would not improve until the middle of the week when a southerly air stream was due to arrive in coastal areas of Guangdong province.

Air pollution in urban areas such as Central, Eastern and Kwun Tong districts had hit “very high” health risk levels as of 5pm, according to the department’s air quality health index.

The department warned that health risks were “very high” in Tung Chung, Tuen Mun, Sha Tin, Tai Po and North districts in the New Territories.

From Tai Mei Tuk in Tai Po, for example, the opposite shore at Ma Liu Shui and Ma On Shan, about 5km (3.1 miles) away, could not be seen at one point because of the pollution.