The Bureau of Meteorology's first weather outlook for December to February indicates a decisive shift towards a wetter than average season for Canberra and much of NSW.

Its forecast for the ACT is that the next three months are likely to bring more than the average rain. And it thinks that both the average minimum and maximum temperatures are likely to be exceeded in the capital.

For south-eastern Australia as a whole, the above average rainfall is likely to come despite ongoing influences from both the Indian and Pacific oceans that would typically nudge the odds to favour a drier-than-usual spell, particularly in December.

Just as in October, it will be high pressure systems over the Tasman that will most likely be conducive for the wetter times.

"In December, high pressures in the southern Tasman Sea are likely to drive more humid air inland than normal, resulting in a welcome wetter-than-average December outlook for central and eastern NSW and eastern Victoria," Robert Pipunic, senior hydrologist for the bureau, said.

That welcome relief may be felt most by farmers in drought-stricken areas rather than holidaymakers.

Earlier this week, the NSW Department of Primary Industries said as much as 30 per cent of NSW remained in its drought-affected category.

Soil moisture levels also remained "extremely low" for most of NSW, with the North Coast the main exception with average levels following recent good rains.

The bureau's summer outlook also shows the odds favour warmer than average summer conditions for almost the entire country, particularly for overnight conditions.

The exception looks to be clearest in December, with the likelihood of extra rain keeping daytime temperatures close to average.

While the dampness should contribute to higher than usual humidity, fire authorities will still need to be on alert.

Australia, after all, posted its second-hottest January-October period on record for daytime temperatures.

"This warmth, combined with a predominantly dry landscape, means bushfire risk remains high in many parts of Australia," Dr Pipunic said.

Andrew Watkins, manager of climate prediction services at the bureau, said the forecast for December meant there's the potential for more humid than usual weather.

"You tend not to get the extreme heatwaves [during such conditions]," Dr Watkins said.

Still, "it wouldn't take very long" for warm and dry spells to elevate fire risks again, particularly towards the end of summer, he said.

The outlook for damper conditions in eastern Australia doesn't extend to Melbourne, western Victoria and South Australia, all of which have also been dry of late.