Hong Kong yesterday recorded its second- longest cold spell - 21 days. The longest cold period - when temperatures fall below 12 degrees Celsius - lasted 27 days in 1968. This record is expected to remain intact as the thermometer is forecast to register a low of 13 degrees by Sunday.

Hong Kong has also experienced more than 456 hours of cold weather this winter - more than double the 205-hour record in January 2004.

Some experts have said the cold weather in China and Canada may be linked to La Nina, a sea-surface cooling pattern in the east Pacific, which leads to a warmer sea surface in the west Pacific near China and Asia.

"La Nina is causing warm moist air to move to the south of China," said Professor Yan Yuk- yee, who specializes in climatology at Hong Kong Baptist University. "When this meets the cold air of the monsoon, it causes freezing conditions."

The cold spell has led to higher admissions to public hospitals. In most wards, occupancy is already full, the Hospital Authority said. Contingency measures including strengthening of the manpower in accident and emergency departments and medical wards are being implemented to relieve the pressure, its spokesman said.  Source