The drought is likely to expand and deepen with odds strongly favouring a drier and warmer than average spring, building on Australia's warmest start to any year for daytime temperatures, the Bureau of Meteorology said.

According to the bureau's updated outlook for spring, none of NSW can expect above-average spring rainfall. The odds of poor rains are particularly strong in the state's south, and for almost all of Victoria.

Cattle belonging to the Cookson family is seen along a stock route near St George, Queensland - a region in its sixth year of drought. Credit:AAP

Sydney, which will cap its driest winter in more than a decade by tomorrow, has almost even odds for average spring rainfall.

Spring daytime temperatures, though, are likely to be above average, extending one of the city's hottest years on record.