BUNDLE up this weekend as the weathermen are predicting temperatures to drop below 10 degrees Celsius. The Royal Observatory predicted the low overnight would hit nine degrees. Today's temperature is not expected to climb beyond 13 degrees, with a cooler overnight forecast. The cold snap arrived late in the afternoon with an intense winter monsoon front from the north. Unusually mild afternoon temperatures plunged seven degrees to 14 degrees. It should still be overcast tomorrow and Sunday, but no rain is forecast. The dramatic dip in conditions was similar to December 28, 1991, when the mercury fell to a shivering 4.7 degrees. The coldest day in the past two decades was December 14, 1974, when the minimum was 4.3. The lowest reading - zero - occurred on January 18, 1893. The Social Welfare Department will hand out blankets to the needy when the mercury falls below 10 degrees. Ten community centres were opened last night as temporary shelters.