Hongkongers will experience an unusually cold Christmas Eve morning, and a disease expert is urging parents to take their children to get flu shots.
The Observatory said an 'intense' cold winter monsoon would affect southern China in the next couple of days. It expects the temperature to drop overnight to a minimum of 11 degrees Celsius today (2-3 degrees lower in the New Territories).
Temperatures will range between 13 and 18 degrees on Christmas Eve, compared with 16.3 to 20.2 degrees on the same day last year.
But Christmas Day is expected to be a comfortable 15 to 20 degrees this year, similar to the 16 to 19.4 degrees last year.
As the mercury drops to the low teens in the next two days, flu experts say the young will be the most vulnerable to weather-related cold.
Thomas Tsang Ho-fai, controller of the Centre for Health Protection, expects the peak flu season to hit in about one or two months' time.
He urged parents to get their children vaccinated now for seasonal flu. Children need two shots four weeks apart for proper immune response, he said.