Backdoor in the United States offers consistent surf year-round, but the best conditions typically occur during the winter months, from November through February. During this period, ground swell dominates (76-88% of the time) with mean swell sizes ranging from 1.7 to 2.0 meters, providing powerful and clean waves. The downside is that wind conditions are less favorable, with bad winds occurring 52-64% of the time, but when the winds align, the surf is exceptional. Late fall (October) and early spring (December) also see strong ground swells (72-85%) and slightly improved wind conditions (44-48% good winds), making them solid alternatives. The summer months (May-August) bring smaller swells, primarily wind-driven, with lower mean sizes (1.1-1.3m), though July and August see slightly better wind conditions (38-41% good winds). September stands out as a transitional month with improving ground swell presence (37%) and the best wind odds year-round (51% good winds), offering a balance between swell quality and cleaner conditions. Overall, advanced surfers will prioritize the winter swell power, while those seeking more manageable waves and fewer crowds might prefer late fall or early spring sessions.