Sweet Gum trees are seen by the Tai Tong Nature Trail in Yuen Long in the New Territories. Photo: HK Government

Forecasters may issue the first cold weather warning for winter – for Sunday, as a cold front approaches the city.

The Observatory has forecast that the temperature will drop to 12 degrees Celsius on Sunday and Monday in downtown areas, while districts in the New Territories and higher land may fall a few degrees more, according to the weather bulletin on Monday.

In the next couple days, an easterly airstream will affect the coast of Guangdong province in mainland China and the city will become cloudier with a few patches of rain.

The temperature will stay around 20 degrees Celsius early this week and should reach a maximum of 22C on Friday before the cold front will start to make the temperature fall significantly – to 14C on the weekend and dip further to 12 degrees on Sunday and Monday.

Meanwhile, the Agriculture, Fisheries and Conservation Department said leaves on trees in Yuen Long’s Tai Tong area in the New Territories have started turning red, Sing Pao Daily reported.

According to the “Red Leaves Index”, most leaves on trees such as Sweet Gum, Hong Kong Gordonia and Rhodoleia along Tai Tong Shan Road in Tai Lam Country Park have started turning red.

The department advised visitors to keep country parks clean and watch out for busy traffic when visiting parks.