It may not be a white Christmas, but colder weather is predicted to arrive this week as temperatures fall as low as 10 degrees Celsius. Hong Kong Observatory said yesterday a cold front from the north had begun to make its presence felt in southern China, which is expected to bring cooler weather to Hong Kong over the next few days. Senior science officer Shum Chi-ming said: 'Over the Christmas holidays, we expect the northeast monsoon to strengthen and an apparent change in the weather. 'We expect the temperatures on Wednesday and Thursday to fall to around 12 degrees and a couple of degrees lower in the New Territories.' The observatory said the temperatures could hit 10 degrees on Friday. Mr Shum also said to expect cloudy mornings and evenings. The Department of Health urged the public to take precautionary measures against the colder weather. Regina Ching Chuek-tuen, the department's assistant director (personal health services), said the cold weather could trigger diseases, especially among the elderly or those with heart, respiratory or chronic illnesses.