Why does my skin breakout more in the summer?

Acne. Heat, sweating, excess oil production, hormone changes are all possible causes of breaking out more in the summer. You could try otc acne med or cleansers. You could also consider showering with soap after exercise. There are many available treatment for the outbreaks.
Sweating. Sweating may be a cause of worse acne in the summer, although the sun has a beneficial effect for others in decreasing inflammatory lesions such as pimples in the summer.
Summer Acne. There are many who suffer from acne particularly in the summer. This happens due to excessive sweating and clogging of the pores on the face. Treatment of summer acne is possible with topical and oral medications. See your dermatologist.