The dryland cropping system in the Pacific Northwest is dominated by a winter wheat-summer fallow cropping system that occupies more than 90% of the dryland hectares. Success in finding a viable alternative crop has been limited because the annual precipitation in this region varies from less than 12 to more than 24 inches, with 75% of the precipitation falling between October 31 and the following May 1. Winter safflower (Carthamus tinctorius L.) is a potential alternative crop for the PNW. Safflower was grown in Egypt more than 4,000 years ago and cultivated in China at least 2,000 years ago. Winter-hardy safflower is a recent development with the first registration of winter-hardy germplasm in 2008. The objectives of this research were to determine the adaptation and yield potential of winter safflower seeded at various dates in the fall and spring at the Pendleton and Sherman Stations of the Columbia Basin Agricultural Research Center. Winter-hardy lines of safflower were sown when soil moisture conditions were appropriate for seeding in the fall and spring of 2007, 2008, 2009, and 2010. Yields of winter hardy lines were as great as 2,100 kg ha-1 at the Pendleton Station and 1,100 kg ha-1 at the Sherman Station when sown in the fall. Yields of winter hardy lines were more than 50% greater when sown in the fall compared to spring sowing. The lines had sufficient winterhardiness to survive three of the four years but were killed in December 2009 by temperatures of -20°C without snow cover to protect them. Winter hardy lines produced greater yield than spring varieties when sown in the spring.