The Hong Kong Observatory cancelled all typhoon signals at 8.20pm on Sunday as a tropical depression moves away from Hong Kong.

Instead, it issued the Strong Monsoon Signal.

At 8pm, the tropical depression was estimated to be about 680 kilometres southwest of Hong Kong and is forecast to move west-northwest at about 15 kilometres per hour in the general direction of the vicinity of the southwestern coast of Hainan Island.

The forecaster said Hong Kong will still be affected by strong winds and squally showers on Sunday and Monday.

However, the weather is expected to improve later in the week.

"With the tropical cyclone moving into the inland areas and weakening, showers will ease off gradually over the coast of Guangdong midweek this week," it added.