Good weather predicted for at least the start of Christmas Day. Photo: Fiona Morris

What weather will Santa deliver for Christmas Day?

It's an early call, but Weatherzone meteorologist Guy Dixon predicts a sunny start to December 25 that will favour outdoor Christmas lunches.

"We should see hot temperatures during the day and into the afternoon, before big puffy clouds start to build," Mr Dixon said. "They look great, but could rain on your parade – or your barbecue."

Similar conditions may persist for much of the week leading up to Christmas, as a low-pressure trough sets up afternoons with showers and possible storms, Mr Dixon said.

Advertisement

The Bureau of Meteorology is more cautious about predicting yuletide weather almost two weeks out. "We don't go that far," one forecaster said. "A lot can change between then and now."

A typical late December day would boast a maximum temperature of about 25.6 degrees, with about a two-in-three chance that it will be dry, the forecaster said.

As it happens, Christmas Day includes some long-lasting records.

The hottest Christmas Day posted at Observatory Hill near the CBD was 38.6 degrees, back in 1868, while the coolest one was 1962's tepid top of just 17.6 degrees.

The soggiest Christmas Day was back in 1870 when 65.8mm of rain was dumped on Sydney.

For those with a short memory, last Christmas had a maximum of 21.5 degrees with 0.6mm landing in the city's rain stocking, according to the bureau's reckoning. However, in the 24 hours to 9am on Boxing Day - as the bureau gauges rainfall - a further 21mm of rain fell, leading to sodden celebrations for many.

Less wild and wet

The coming weekend will deliver a sunnier and drier couple of days after a generally wet and wild start to December for Sydney.

Winds will ease off, making Sunday the pick of the next few days, the bureau's forecaster said.

Temperatures will start to creep up the high 20s for the city over the coming week, with western suburbs likely to experience tops in the low- to mid-30s.

Conditions are back to a more normal mix of highs and low-pressure systems moving across the continent, Andrew Haigh, a duty forecaster for the bureau, said.

"We had an inland trough that didn't move," Mr Haigh said. "We got this continual in-feed of moist air from the north and very humid conditions."

That pattern brought a record seven consecutive days of thunderstorms at Sydney Airport, breaking the previous record stretch of five days set in 1955, 1992 and 2007, the bureau said.

Last Sunday probably saw the most intense of the electric storm activity of the wild week, with the bureau counting about 1800 strikes in a single hour over an area of the state's east centred on Sydney.