The effect of weather on grapevine
growth stages

Temperature, rainfall and wind all have a strong influence on the growth of a vine (annual vineyard cycle) and while each of these will have a greater or lesser impact on individual growth stages, it is typical for a combination of these indices to influence a vines growth. These indices are collectively known as the weather, and the weather over the growing year is called the season. In the following paragraphs are some of the common correlations between the weather and the vines growth.

Temperature and budburst (October)
Soil temperatures affect the timing of budburst and an arbitary temperature of 10 C can be used to predict the onset of budburst. Soil temperature is influenced by ambient temperature and rainfall. Wet soils do not warm as quickly as dry soils with rainfall in spring delaying budburst. Soil temperatures in Central Otago typically rise from 3 C in July, to 5 C in August, 8 C in September and 11 C in October. Warm, dry Septembers mean higher soil temperatures which in turn encourages the onset of budburst.

Temperature, rainfall, wind and flowering (December)
Low temperatures, rainfall and wind all influence flowering.

...work in progress - back to weather summary