Tables III and IV give the results of the multiple regressions that account for trend interactions (Equation 1) and trend interactions and potential optimum growing season temperatures (Equation 2), respectively. The linear specification revealed that variation in growing season temperatures significantly influenced vintage rat- ings in 16 of the 30 regions with as much as 60–62% in German ratings explained and an unweighted average explained variance of 30% (Table III). While the effect of growing season average temperatures varies from region to region, the aver- age response is a 13-point rating increase for each 1◦C increase. For example, a temperature increase of 1 ◦C was associated with the following ratings increases: white Rhine Valley wines by 21.5 points; white Mosel Valley wines by 20.8; red Burgundywinesby12.7;andredSt.E ́milionandPomerolwinesby10.4points.