In this paper, the quality of the wine from the Dao (Viseu) region of Portu
gal is examined and relationships between wine quality and climatic variabi
lity are obtained using spectral and correlation analysis to determine the
structure of the temporal variations. The spectra of the series of quality
of wine values show statistically significant oscillations coherent with th
ose found in the series of teleconnection indices. The series cover a perio
d of 33 years. A significant correlation was obtained between wine quality
and minimum air temperature in May, December and total precipitation in Apr
il. The teleconnection circulation indices are used to provide some physica
l insight into the most significant oscillating components of the climatic
and the wine quality series. We found significant and positive correlations
between the quality of the wine and the Southern Oscillation Index (SOI) o
f August and negative with the SOI of January and with the North Atlantic O
scillation of April. Wine quality and climatic series can be predicted usin
g statistical models depending on significant oscillations.