Winemakers in Australia are grappling with the challenges of a record-breaking hot summer, which has made grapes ripen quickly and is likely to make the nation’s wines more expensive and more alcoholic.

The recent heat has set records across the country and prompted the weather authority in Tasmania to jokingly warn this week that autumn would be “delayed”.

Australia’s Bureau of Meteorology said the summer was the hottest since records began in 1910, including daily temperatures that were 2.1C hotter than average – compared with a previous record, six years ago, of 1.3C hotter.

The long run of hot, dry weather has taken a heavy toll on the nation’s £3.2 billion wine industry, which has become renowned for varieties such as shiraz, chardonnay and cabernet sauvignon. Australia is the world’s sixth largest wine exporter, including large supplies to China, the United States and the UK.

But the searing heat has caused grapes to ripen more quickly, leaving growers struggling to pick them before they become sunburnt and shrivelled.

Andrew Margan, a winemaker in the Hunter Valley, north of Sydney, said the heat had caused both white and red varieties to ripen simultaneously.