The Southern Highlands broke its own February heat record last weekend with an official reading of 38.3 degrees Centigrade at Bowral. It edged out the previous highest reading of 38.2C recorded way back on February 1, 1968 – 35 years ago.

And it may get hotter yet. The Bureau of Meteorology says temperatures are expected to rise even further to-morrow before a cool change, probably on Sunday.

A Bureau spokesman said that in terms of length and the large area affected, the current heat wave is among the five most severe in the last century, alongside the events of January 2001, January 1982, December 1972/January 1973, and January 1939.

Records have been broken in several areas of the State. Wilcannia had 12 days over 40 degrees C, and Scone 10 days over 35C. Ivanhoe recorded 48.5C last weekend. Record highs for minimum overnight temperatures have included four nights above 30C at Tibooburra and ten nights above 22C in Sydney.

The Bureau says that the heat has been caused by warm tropical air lying over NSW, and not moving away because the upper winds have been travelling from west to east. This flow usually has more of an undulating north-south path which assists the exchange of warm air from the north and colder air from the south.

For the record, Bowral's hottest day ever was recorded on January 30 last, when the mercury just topped 40C. Our lowest was minus 11.2C on July 11, 1971.