July is the seventh month of the year. It's one of the months of the year with thirty-one days.
In his youth, it was one of Harry Potter's least favourite months because he was at the Dursleys' instead of Hogwarts School of Witchcraft and Wizardry with his friends. Ironically, it was also the month of his birthday. It was also, however, during this month that Harry first learned that he was a wizard.