A distinct cultivar of Marguerite Daisy plant named `Harvest Snow`, characterized by its upright to outwardly spreading, very uniform, mounding and rounded, and very compact plant habit; freely branching growth habit; thick and somewhat succulent foliage and lateral branches; uniform daisy-type inflorescences with white ray florets and bright yellow disc florets; freely flowering with numerous inflorescences per plant held above the foliage on strong and erect peduncles; continuous and uniform flowering over a long period of time; long-lasting inflorescences; and heat-tolerance.