Characterised by hot days and very cool nights the accumulation of flavour and pure fruit intensity is unique to the Wairau Alpine Valley.
The growing season (September - April) is marginally shorter than that of the Lower Wairau Valley floor.
Marlborough has a mild, sunny climate. Blenheim averages 2,470 hours of sunshine per year, the highest of any main centre.
January is the sunniest month averaging 8.5 hours per day compared with 5.0 hours per day in July. Summer temperatures are among the warmest in the country with an average daily maximum for January and February of 23.5°C, compared with the all year average daily maximum of 18.5oC.
Rainfall varies significantly throughout the region, with parts of the Marlborough Sounds recording the highest annual rainfall. Regionally the average rainfall is around 650mm. The Wairau plains have a mild, dry climate with high variations in the direction and force of surface winds.
The plains are generally protected from Southerly systems that may affect adjacent areas. Rainfall increases from the East to the West with Blenheim receiving 650mm while the adjacent Richmond Range receives 2000mm. South of the Wairau River, the rainfall gradient is less marked and mean annual rainfall varies between 1400mm and 1600mm. Summers are warm and dry and the winters characterised by their clear, crisp, sunny days.