[7] The presence of adequate sun, heat and water are all vital to the healthy growth and development of grapevines during the growing season.
Additionally, continuing research has shed more light on the influence of dormancy that occurs after harvest when the grapevine essentially shuts down and reserves its energy for the beginning of the next year's growing cycle.
On average, a grapevine needs around 710 mm (28 in) of water for sustenance during the growing season, not all of which may be provided by natural rain fall.
In contrast, maritime climates often suffer the opposite extreme of having too much rainfall during the growing season which poses its own viticultural hazards.
During the grapevine growing season, there is very little rainfall (with most precipitation occurring in the winter months) which increases the risk of the viticultural hazard of drought and may present the need for supplemental irrigation.
This is due, in part, to small land mass size of southern hemisphere continents relative to the large oceans nearby.
There are also several wine regions (such as Spain) that have areas that exhibit a continental Mediterranean climate due to their altitude or distance from the sea.
[6] Wine regions with maritime climates are characterised by their close proximity to large bodies of water (such as oceans, estuaries and inland seas) that moderate their temperatures.
The climate characteristics of a wine region will have significant influence on the viticulture in the area. Pictured are terraced vineyards in
Northern Portugal
's
Douro Valley
.
Large bodies of water, such as
Lake Geneva
in Switzerland, can have a moderating effect on the climate of a region.
