2020 wine harvest could plummet as state continues to be hit by high temperatures, low rain and bushfire smoke

Owner and operator of Borambola Wines, Tim McMullen expects his grapes will require significant attention if they are to survive the onslaught of this week's heat and smokey conditions.

"They'll struggle and shut down during the heat," Mr McMullen said.

"This is a crucial time as well when the sugar will be coming in. At that time, the vines want a lot of moisture."

Last year, the national harvest yield was 25 per cent down on previous years, and with the heat and smoke conditions this year, Mr McMullen expects a similar drop this season.

"The smoke is an issue, though it's not as bad here as it has been in the Hunter Valley," he said.

"Smoke taint absorbed through the leaves gets into the grapes causing them to be unpalatable."

While conversing with fellow winemakers across the Riverina and Central West, Mr McMullen has come to the conclusion that those closer to Wagga will have a higher chance of producing an unscathed harvest.

"I've been talking to some [winemakers] out in Orange, and they've been having to pick and choose which vine blocks they'll water and which ones they'll close off to get no harvest from. There's just not enough water for them to do it all under the restrictions," Mr McMullen said.

Not only has the heat and smoke presented dilemmas for the region's winemakers, but some producers in the South West Slopes have felt the heatwave only after uncharacteristic cold seasons.

"Ironically two weeks ago in Tumbarumba, the vineyards had to deal with frost damage," Mr McMullen said.

"It's tough, we've got it all happening. Since I planted our vines in 1995, I can't remember a single year we've had the trifecta [of bad weather conditions]."

To give his vineyard a fighting chance, Mr McMullen began implementing an increased irrigation strategy from much earlier in the year.

"We've been irrigating more than we ever have before," Mr McMullen said.

"Because of the dry winter, the vines won't have that deep soil moisture so we had to start watering two months before we usually would.

"We've built a canopy to shade the fruit too, one that will allow the airflow through and will protect the grapes from being sunburnt. There isn't much we can do about the smoke though."

It's a similar strategy to the one that's been adopted at Cottontails Winery in Eunanoreenya.

Lilly McCormick, manager of the restaurant and marketing operations, said the team managed to put in systems early that will keep the vineyard from experiencing anything too untoward this year.

"We've been able to fortify ourselves and take precautions," Ms McCormick said.

"The vines have been given plenty of water which has meant that they'll be self-sufficient."

As a result of the persisting inclemency, Mr McMullen and Ms McCormick expect the harvest will arrive earlier than in previous years.

"Our Chardonnay we usually harvest in mid-February, but I'd say that will be a couple of weeks earlier next year. It'll mean that the Shiraz and the Cabernet will all come in early."

Likewise at Cottontails, where Ms McCormick said the grapes have "grown quite big quite early".

"It's definitely been harder this year, but the crop is looking good."

But despite the weather, Mr McMullen remains optimistic for his industry's ability to make the most of the bad hand they have been dealt.

"For the past two or three years, there has been a shortage of fruit, and that means every berry will be chased," he said.

"Low yield means higher prices, or maybe that's just me hoping."