From The Collaborative International Dictionary of English v.0.48 :
Wintery \Win"ter*y\, a.
Wintry.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
wintery
adj 1: characteristic of or occurring in winter; "suffered
severe wintry weather"; "brown wintry grasses" [syn:
wintry, wintery] [ant: autumnal, summery,
vernal]