Sydney weather blows hot and cold

When athletes flew into Sydney early in September for the Olympics, many complained about chilly, windy weather - now it is so hot Australian authorities are on full alert for fires.

New South Wales Rural Fire Service Commissioner Phil Koperberg has ordered a fire ban for the whole of Tuesday - meaning no outdoor fires except gas barbecues can be lit within 20 metres of a house or building.

The ban includes the Olympic host city where temperatures soared to an unseasonal 29C in some parts on Monday, well above the usual for a spring day.

"The weather forecast for (Tuesday) indicates that the fire danger will be in the extreme range and, given the amount of dry grass and other fuel that is around, we had no choice but to declare a total fire ban," Koperberg told the Sydney Morning Herald.

He warned that the ban might have to be extended - a temperature of 28C is forecast for Wednesday. Cooler weather is likely later in the week