Summertime is one of the weaker Ub Iwerks ComiColor cartoons, in my opinion, but it features the return of Old Man Winter, who was in the cartoon Jack Frost that I posted the other day. It was definitely influenced by the Disney series of season-based Silly Symphonies… because Iwerks directed Springtime (1929) Summer (1930), and Autumn (1930) for them. It also features a very racy scene for the time of silhouettes of trees turning into silhouettes of rotoscoped dancing ladies. In spite of some very good moments, this cartoon is greatly weakened by having only one design for a centaur, and reusing the animation of him relentlessly.
This cartoon, along with almost all of Ub Iwerks cartoons made for his own studio, are available on the excellent DVDs The Cartoons that time Forgot Volume One and Volume Two. This cartoon is on Volume 1.