August is a transition month from summer flowers to fall flowers. The beginning of the month has a few stubborn late blooming DAYLILES but they are mostly finished by mid-month.
One reason I plant several annuals every Spring is to fill these few transition weeks between Spring to Summer and Summer to Autumn flowers because they never slow their blossoms all season long. That is not to say they are the only flowers in bloom, they just help with more showy color to assist the reliable perennials during these same periods.