Summer is likely to start off hot and dry, with much of eastern Australia gripped by the same climate influences that gave us a warmer and drier than average spring, the Bureau of Meteorology predicts.

Australia could see fewer cyclones, but more heat and fire risk in coming months, the bureau says.

The just-released 2019/20 Summer Outlook reveals a high likelihood of days and nights that are warmer than average for most of the country, while rainfall is likely to be below average for large parts of the nation's east.

The outlook maintains heightened bushfire risk over the coming months and also does not allay the risk of other seasonal threats.

"Even with a drier than average outlook, localised flooding remains a risk under particular meteorological conditions such as thunderstorms, and of course communities in the north need to be prepared at this time of year for tropical cyclones,” the bureau said.

At least one tropical cyclone has crossed the Australian coast every season since reliable records began in the 1970s. Under current weather patterns, the first cyclone crossing typically occurs in late December.

The key culprit for the warm and dry conditions is one of the strongest positive Indian Ocean Dipole (IOD) events on record, BOM’s head of long-range forecasts Dr Andrew Watkins said. This phenomenon exacerbates drought and bushfire conditions as it brings reduced rain-bearing weather systems and warmer than average temperatures for large parts of the country, he explained.

“The positive IOD means we're also expecting a delayed onset for the northern monsoon, one of the key drivers for tropical rainfall during the summer months,” Dr Watkins said. That monsoon is forecast by mid-summer which should see the odds for closer to average rainfall increase from January.

Spring is likely to finish as Western Australia's warmest and driest on record, and one of the five driest for NSW, Queensland, Victoria and South Australia, according to preliminary findings at the bureau.

Insured losses from the NSW and Queensland bushfires, which have been declared an insurance catastrophe, increased to $165 million from 1525 claims lodged with insurers by November 22, according to the Insurance Council of Australia.

Still, cool nights in Victoria mean the minimum temperature is on track to be the lowest for spring since 2003, and coastal areas of Western Australia show increased odds of a wetter than average summer.