Yes. However, Earth’s axis, the line around which the planet rotates, is tipped 23.5° with respect to the plane of revolution around the sun. When Earth is closest to the sun (its perihelion, about January 3), the Northern Hemisphere is tilted away from the sun. This causes winter in the Northern Hemisphere while the Southern Hemisphere is having summer. When Earth is farthest from the sun (its aphelion, around July 4), the situation is reversed, with the Northern Hemisphere tilted toward the sun. At this time, it is summer in the Northern Hemisphere and winter in the Southern Hemisphere.