The Sydney to Hobart yacht race is set for a bushfire haze free start

The Sydney to Hobart race fleet is not expected to encounter very strong winds until Monday or Tuesday when most of the 157 yachts should have finished.

Supermaxi Wild Oats XI is hoping to take out line honours again in the Sydney ot Hobart yacht race. Source: Rolex/Carlo Borlenghi

The 75th Sydney to Hobart race fleet is expected to be spared from smoky haze at the start and most are unlikely to encounter very strong winds on their passage south.

Thick smoke from NSW's many bushfires forced the cancellation of the recent Big Boast Challenge lead-up race.

But fears the start of the iconic Sydney to Hobart race on Sydney Harbour on Boxing Day could also be affected by smoke were allayed by the Bureau of Meteorology at Tuesday's fleet weather briefing.

"Over the next few days, we are sitting in easterly winds which means for Sydney itself and much of the NSW coast we are not going to look at thick smoke haze affecting anywhere over the water," BOM spokesperson Gabrielle Woodhouse said.

Wild Oats XI gets close to Hobart ahead of its 2018 win. Source: Rolex/Carlo Borlenghi

"It is most likely the thick smoke haze will be overnight and in the early morning, during the day itself it will abate."

Mr Woodhouse said the race was likely to start in a 10-15 knots north to a north-easterly breeze.

There remains uncertainty about a potential southerly change, though it is unlikely to bring heavy winds.

The only really heavy wind conditions, with gusts approaching gale force, could come on Monday or Tuesday, by which time a large portion of the fleet of 157 yachts should have finished.

Sydney has choked through weeks of haze and bushfire smoke. Source: Getty Images AsiaPac

The race record of one day, nine hours and 15 minutes set by Commanche in 2017 is unlikely to be threatened despite the presence of five speedy super maxis, including nine-times line honours winner Wild Oats XI and two-times winner Commanche.

The race, by the numbers:

* Size of 2019 fleet: 157

* Biggest fleet:- 371 (1994, the 50th race)

* Smallest fleet: 9 (1945, the inaugural race)

* Most line honours wins: Wild Oats XI - Nine

* Most overall wins: Freya, Love & War - Three

* Line honours record time: Comanche - One day 9 hours, 15 minutes, 24 seconds (2017)

* Slowest time: Wayfarer - 11 days, six hours, 20 minutes (1945)

* Closest finish: Condor beat Apollo by seven seconds (1982)

* Most races by any boat: Bacardi - 28

* Most races by an individual: Tony Ellis - 51

* Most races by a woman: Adrienne Cahalan - 27

* Most successive races: Lindsay May - 46 (1973-2018)

With AAP...