Air Masses

Christchurch is typically influenced by maritime air masses. These masses flow in from the east and loose moisture as the flow over the Southern Alps that lie east of the city. Most of the precipitation is dumped on the mountains as snow in the winter and rain the summer/spring/fall. Since New Zealand is an island nation there is not a huge difference between the moisture on either coast but it is significant enough to call the western coast drier. As you can see in the map below, taken from WeatherUnderground, Christchurch is engulfed in low-lying clouds (Blue and Gray). New Zealand is named Aotearoa by the native Maori people. This name means "land of the long white cloud" and properly called so because the country spends much of its time with cloud cover that never seems to end. These clouds lie so low because they are very dense with moisture due to the surrounding ocean. There is not enough land mass for continental air masses to form and this creates a temperate climate that promotes a vast plant species.