I have attic ventilation but my attic still seems too hot?

During warm months with proper attic ventilation the attic could be up to 20 degrees warmer than outside temps.

With any attic ventilation system, the attic could be about 20 degrees hotter than it is outside. Attic ventilation is meant to protect the roof sheathing, insulation and shingles from temperature and moisture extremes. However, many variables will affect the temperature that the attic can reach. For example, the color of the shingles will have a large impact on the temperature. Black shingles will cause the attic to be much hotter than if white shingles were used. Other factors are the geographical location, intensity of the sun, orientation of the primary roof plane, and amount of total ventilation net free area.