(Decanter) - Frost enveloped young buds in Barossa's vineyards this week, almost a year to the day since heavy frosts caused serious damage to vines in the region.

Several Barossa winemakers have been anxiously checking their vines for frost damage after a cold spell hit the region overnight on Monday.

It follows a spate of unsettled weather in parts of South Australia.

'We had one grower on the phone in tears this morning - they've had three frosts in three years,' said Stuart Bourne, senior winemaker at Chateau Tanunda, based on the valley floor and which works with growers across the region.

Initial signs on Wednesday afternoon were that the area as a whole may have escaped relatively lightly this time around, but Bourne said there were pockets of more serious damage within some vineyards.

'It hit particularly in the north of the district, but we won't know the full extent for a few days,' said Bourne.

Some growers turned on fans in their vineyards, to blow warm wind through vines in an effort to prevent frost.

Overall, the 2015 growing season has progressed well up to now, estates are reporting. By midday Wednesday, bright sunshine had returned to the area, with temperatures hitting 15 Celsius in the afternoon.