The Hong Kong Observatory issued the amber rainstorm warning signal on Sunday afternoon as heavy rains blanketed the territory.

The observatory raised the signal at 2:20 pm as heavy showers and squally thunderstorms affected the city due to a cold front moving across the region. The weather had been sunny in the morning before the HKO issued at 12:35 pm the thunderstorm warning signal, which was extended until 6:30 pm.

“The rainstorm warning signal is now amber. This means that heavy rain has fallen or is expected to fall generally over Hong Kong, exceeding 30 millimeters in an hour, and is likely to continue,” the observatory said.

Flooding may occur in some low-lying and poorly drained areas, the HKO said, adding that members of the public should stay away from watercourses which could see flash floods.

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Showers will be heavy at times, with severe squally thunderstorms, while violent gusts may affect the city, the observatory said.

A spokesman for the Labour Department said that employers and contractors should avoid assigning employees to carry out electrical work at places affected by the rainstorm.

The observatory also said that there would still be a few showers on Monday and Tuesday, with temperatures dropping to as low as 21 degrees Celsius in the morning.