Paul Symington writes:
Irregular climate patterns are not uncommon in the Douro, but this year has been most unusual. Observing the lovely green vineyards in the valley in June you could have easily been forgiven for thinking that all was well. First impressions however, are not always right.
The data at Quinta do Bomfim in Pinhão, in the heart of the Douro region, indicate that the 2011/12 winter has been the driest in the Douro in the last 40 years, as well as the third coldest since 1931. Readings show that soil humidity readings at various depths in our Douro quintas were at very low levels throughout this past winter. In June and July the readings have been at levels normally only seen in August and September, the region’s very driest months.
The viticultural cycle starts in November, and to the end of June there has been a cumulative rain shortfall of 274 mm or 48%. In other words, we have so far received only about half the average rainfall we would expect by this time of year. In the 4 months from December to the end of March, a total of just 54 mm fell at Pinhão. The average for the single month of January is virtually double that, at 104 mm. As a result, by early April we were preparing to water our one-year-old vines, an unheard of requirement at that time of the year.
Thankfully April and May brought normal rainfall and even more important, the average temperatures have been below average for most of this year, hence the fine looking vineyards in June. But the Douro has missed out on a substantial part of the usual winter build up of water reserves. The spring rain was not enough to reverse the rapidly declining soil moisture levels, whose steep downward curve commenced last November. The Portuguese Meteorological Office has now classified over 50% of the country as being in ‘extreme drought’ conditions, mostly its central and southern areas. The situation is not so dramatic in the Douro, but even here, most of the region— as of the first week of July — is now classified at the next level down from ‘extreme drought’ to ‘severe drought’, which is hardly comforting.
Overall, these conditions have resulted in poor fruit set in some varietals and this will result in a smaller than average crop. This will be advantageous as there will be less demand on each vine to ripen its fruit. The next 6 to 7 weeks leading up to the harvest will be crucial; we are hoping for some relatively cool weeks and hopefully even a little rain in August. An absence of rain and very high temperatures would create conditions for a very challenging harvest, although the Douro’s hardy farmers and their indigenous vines are accustomed to those.