Since Arthur's Pass National Park is part of the Main Divide, the eastern and western side have climatic differences and vary in their vegetation accordingly. All weather conditions depend on altitude, location and distance to the Tasman Sea.
During warmer months, north-west winds bring moist air from the Tasman Sea. These air masses press against the steep mountain ranges of the Main Divide and cause orographic rainfall. The western side of Arthur's Pass therefore experiences a higher annual rainfall than the east. Once past these altitudes, the air masses turn into hot and dry west winds that strongly influence the eastern vegetation.
Arthur's Pass Village has an annual rainfall of about 4500 mm that is distributed among 200 rain days per year. Average summer temperatures range between 12°C and 18°C from November to April. Winter averages lie between 5°C and 12°C from May to October. Snow periods occur between June and September.