Mars gets to within 128.5 million miles (206.5 million kilometers) during its closest orbit of the sun. Mars' average distance to the sun is 142 million miles (228 million kilometers).
Mars, like Earth, has an axis that is tilted in relation to the sun. This gives Mars seasons. Due to its oval shaped orbit of the sun, which is more elongated than Earth's orbit, Mars' seasons are more extreme than Earth's seasons. When Mars is closest to the sun, the southern hemisphere experiences a very hot and short summer, as it tilts towards the sun. When Mars is furthest from the sun, the southern hemisphere enters a long and cold winter, as it tilts away from the sun.