As cold air blanketed wide areas of the nation on Thursday morning, the mercury in central Tokyo fell to a low of minus 4 degrees Celsius, the capital’s lowest figure in 48 years.

The bitter cold Wednesday — coming just days after the city’s heaviest snowfall in four years — prompted the Meteorological Agency to issue a low temperature advisory for the 23 wards for the first time in over three decades. Shigeki Kawaguchi, an official of the agency’s weather consultation center, said a similar warning was last issued in late January 1985.

An advisory of this kind is issued when water inside pipes might freeze or pipes might rupture — or when crops might be damaged — according to the agency.

The Tokyo Metropolitan Government’s waterworks bureau also posted a notice on its website, urging the public to take precautionary measures to protect pipes located outdoors or those that are exposed to the air.

The bureau said water pipes can be protected by wrapping them with insulation materials, something that can be easily done. When the temperature drops, several things may occur: Water in outdoor pipes can freeze, pipes can break and the supply can be cut off.

The bureau’s online notice said that apart from insulation materials, blankets, cloth or Styrofoam can also be used. It also cautioned against letting the material get wet, and said products such as vinyl tape could be used to ward off moisture.

An official said the bureau was inundated with inquiries on Thursday. It received 729 inquiries between 8 a.m. and 10 a.m. Problems included cases of frozen pipes, water supplies being cut off and questions about how to protect water pipes, the official said.

Following an increase in the use of heaters, mainly in the metropolitan area, due to the cold weather, Tokyo Electric Power Company Holdings Inc. warned the same day that electricity usage was predicted to reach a level of 96 percent at the peak time slot of around 6 p.m.

Tepco said power demand was likely to reach 50.5 million kilowatts versus the peak load capacity of 52.27 million. The utility described the electricity demand forecast as “severe.”

Temperatures are expected to stay low in central Tokyo through the weekend, with a forecast low of minus 3 for Friday, minus 2 for Saturday and minus 1 for Sunday, the Meteorological Agency’s Kawaguchi said.

The lows and highs will likely return to the average figure of zero or 1 degree by around Monday, he added.

KEYWORDS Tokyo, weather, temperatures