Global wine production is predicted to hit a four-year low in 2016 – a decrease of 5% compared with 2015.
It ranks among the three poorest years for production since 2000, according to trade group International Organisation of Vine and Wine's predictions.
Production, excluding juice and musts, is likely to reach 259.5 million hectolitres (mhl). Italy confirms its place as the leading world producer with 48.8 mhl, followed by France (41.9 mhl) and Spain (37.8 mhl).
Climate change is cited as the main factor behind the drop, with the OIV saying production likely to fall 12% after vineyards endured frost and hailstorms in the spring, then drought in the summer.
In South America, production was strongly affected by "climatic events". Argentina recorded a significant reduction in its production, down 35% compared with 2015.
Meanwhile, South Africa is on track to report a bruising 19% fall in production - but other New World producers are doing better.
The OIV said that Australia, New Zealand and the US would all see output rise.
