Forecasters on Friday said that runners taking part in Sunday's Hong Kong Marathon could face the coldest day this winter.

Some 74,000 runners are expected to take part in the race, with more than 15,000 of them coming from more than a hundred countries and regions.

The Observatory said the temperature could dip to as low as nine degrees Celcius in the urban areas on Sunday, and even lower in the New Territories.

Senior scientific officer, Hon Kai-kwong, said as strong winds were expected, runners could feel colder than what the mercury indicates, otherwise known as the wind chill effect.

"Because northern winds for the day should be relatively strong, we expect the wind chill effect to be rather significant - especially in open areas and on high grounds," he told an RTHK programme.

For his part, the Hospital Authority's chief manager, Dr Larry Lee, said because of the weather, runners shouldn't over exert themselves.

"Before the start of the race, [runners] should keep their heads and hands warm, and they should stay hydrated," he said on the same programme.

"And because of the strain on their bodies, from an event like this, runners should make sure that they spend enough time warming up. If they find they can't go on, runners should rest."

Top local runner Virginia Lo said the cold weather should help athletes achieve good times.

She called on participants to wear raincoats and running sleeves to keep warm.

Former world marathon champion Rose Chelimo is among the world's finest joining the competition and she'll be making her Hong Kong debut this weekend.

The 35-year-old Kenyan-born Bahraini won gold at the World Championships in London eight years ago.

"I've been preparing for long, since last year. It needs a lot of discipline and dedication from yourself, not following your coach or anybody," she said.

Ethiopia-born runner Gashau Ayale, who represents Israel, will also be making his Hong Kong debut, and thinks the local course is a challenging one.