The god associated with the harvest in Celtic tradition, honored during the festival of Samhain, is typically Cernunnos, the horned god linked to nature and fertility. Samhain marks the transition between the harvest season and winter, a time when the veil between worlds is thin. During this festival, rituals honoring Cernunnos reinforce the cycle of life, death, and rebirth, showcasing the interconnectedness of natural cycles and human existence within Celtic spirituality and traditions.