The 2020 vintage season started cool with the occasional October frosts. November temperatures were average for the area and growth was normal. Late November and December weather events were unusual with high rainfall in the west and persistent cool SW winds keeping temperatures low. December 2019 was one of our coldest Decembers ever and it was not until after the first week of January the weather systems changed and the warmer weather we should have been receiving arrived. The cold weather affected flowering and fruit set. Average bunch size is are below our long term average.
October. A very heavy frost (minus 5 degrees) hit on 6 Oct as buds were emerging but frost fighting sprinklers on at 1:30 am avoided any damage. October was one of our coolest Octobers. On its own, a cooler than average October means nothing for the whole season other than a slightly slower start.
November. A more important month as shoots and flowers develop. The month was warmer than average despite a frightening hailstorm on 16 November (see blog here). By the end of November the season to date was back to "normal".
December brought higher than average rainfall with flooding in Wanaka and high river levels. The rain had little direct effect on the vineyard, but the weather direction and lack of fine days kept temperatures well below average. Average temperatures in December were cooler than November (14.2 degrees C versus 14.8 degrees C). This is the first time we have seen December cooler than November. The unusual weather is associated with an atmospheric phenomenon known as Sudden Stratospheric Warming. (See NIWA explanation here. A similar event occurred in Spring of the difficult 2003 vintage).
January. Average temperatures and four weeks of dry weather until a large rainfall (84 mm) on 4 February.