Traditionally, the best time to visit Chile is considered to be from October to March, as this is the South American summer. However, the Atacama area can be visited all year round due to the high altitudes, as days are warm and nights are always cold.
Torres del Paine National Park can be quite busy during this time as it is the peak season for hikers. Visiting in winter from June to August has its advantages, as the park is much quieter. There is often snow, but the winds from Antarctica are much lower and the lakes are also calmer. However, be aware some areas of the park may be inaccessible due to snowfall.
Easter Island can be visited all year but is quieter outside of the summer months.