A celestial quirk will deny Mid-Autumn Festival revellers the chance to gaze at a full moon next month.
While the festival, which falls on September 8, sometimes coincides with the full moon, this year that lunar phase takes place the next day, a public holiday.
And despite September 9 boasting a supermoon - when the moon is at its closest orbit to the Earth - even then, the city is set to be disappointed.
The exact moment of the full moon - when it is fully illuminated by the sun, unimpeded by Earth's shadow - will take place at 9.38am, well before it rises over the Hong Kong skyline.
"The full moon will take place in the morning and at that time it will be below Hong Kong's horizon," the Observatory's senior scientific officer Mok Hing-yim said yesterday.
On September 8, the Observatory forecasts that the moon will rise at 5.51pm and set at 6.02am.
"The moon will still be big and bright over the festival; it's just that people won't be able to see the full moon this year," said Mok.
The last time a full moon occurred on the night of the festival itself was in 2004.
Mok said it was not clear what the weather during the festival would be like because it was still two weeks away.
The Mid-Autumn Festival takes place on the 15th day of the eighth lunar month in the Chinese calendar.
There are three fundamental concepts behind the festival: gathering with the family, giving thanks for the year's harvest and praying.
Traditional activities include lighting lanterns, dragon and lion dances, and making and sharing mooncakes.
Each year in Tai Hang, Causeway Bay, hundreds of performers take part in a fire dragon dance. Legend has it that in the 19th century, the villagers of Tai Hang fought off a plague with a fire dragon dance.
Victoria Peak and Tsim Sha Tsui are prime locations for moon-gazing.