A report on this year's harvest released by Wine Tasmania on Wednesday showed Northern Tasmanian producers in the Tamar Valley, Pipers River and the East Coast accounted for 66.9 per cent of the total number of grapes harvested during vintage.

Southern Tasmania was responsible for 30 per cent of the harvest, with the rest made up from the North-West and other smaller areas.

Tamar Valley producer Bec Duffy from Holm Oak said this year's vintage had its challenges but she was proud of the quality of the wine that had resulted from it.

"This year we had a lot of wind, particularly at the start of the season, which meant we had to do more leaf plucking to create air flow between the rows," she said.

The wind was accompanied by rain later in the season, which provided reliable water but also presents its own set of problems.

"A lot of rain can lead to fungal diseases, particularly if there's a lot of rain that falls at once because it can make the grapes split," she said.

However, Ms Duffy said Tasmanian wine producers were a resilient bunch and were used to being flexible with whatever the weather throws at them, due to Tasmania's variable weather patterns.

"We are fortunate to live in a climate where we have good soil, access to water but we are not in a place where it is warm and dry all the time," she said.

Ms Duffy said the Tamar Valley was a great wine-growing region because of its fertile soil, and consistent access to water.

She said her vineyards' locations were also close to the river and they were relatively warm compared to other locations in the state.

Wine Tasmania technical officer Paul Smart said while yields across Tasmania were lower than previous years, the quality had not been impacted.

"Overall, yields were down about 28 per cent on the 2019 vintage, roughly equating to 890,000 cases of wine, with 12,308 tonnes produced in 2020," Mr Smart said.

"Regardless of vineyard location, the 2019/20 season will be remembered as one of the most challenging in recent years, from the initial budburst in spring through to a delayed harvest throughout March, April and May."

Mr Smart said this year's vintage looked to be strong, particularly in the Pinot Noir and Chardonnay varieties as well as aromatic white wines such as Riesling, Pinot Gris and Sauvignon Blanc.

"The island is one of the most challenging and the most rewarding places to grow grapes in Australia - there are no two seasons and no two vineyards the same.

"Our dedicated grape growers have to be highly skilled to deal with the variabilities and extremes, as they again demonstrated in 2019/20," Mr Smart said.

Wine Tasmania produced the Vintage 2020 snapshot report, which can be viewed online.