Heat Wave in Portugal to Result in Wine Grape Production Loss of 25-30%

Temperatures soared above 40ºC (Celsius) across large parts of Spain and Portugal during the second week of July 2022 (week 28) as the Iberian Peninsula faces a second heat wave in less than a month. The heat wave began on Sunday the 10th of July and could last nine or ten days, which would make it one of the three longest heat waves since 1975. Vines have great difficulties carrying out photosynthesis when temperatures exceed 35ºC. The heat and water stress suffered by the vines result in less branch expansion and smaller berries. Fewer and smaller berries will translate to less wine, with production losses estimated to be in the range of 25-30%. The producers that have irrigation will be able to mitigate these losses. Ervideira for instance has doubled its irrigation from the normal 150,000 liters/ha of water to 300,000 liters. However, there are wine regions where water is scarce or where irrigation has traditionally not been required. Vines in these regions will suffer severe heat and water stress which could increase production losses beyond 30%. The only positive aspect of the heat wave is the fact that the shortage will be beneficial for stock depletion of previous campaigns, especially for red wines.