The ideal climate for growing tea plants would be misty at night, sunny during the day, some rain at night time and not too much cold weather, hail or drought. Yet despite this ideal, tea plants (Camellia sinensis) can be successfully grown outdoors in many areas of Australia, if the conditions are suitable. Zones 4 to 7 have a suitable climate for outdoor tea planting, however it is important to ensure additional factors like drainage, soil pH and sufficient water are adequately addressed, as outlined in more detail here.
While it can be helpful to consider your local climate zone when deciding if tea will grow in your area, tea plants are quite hardy and many local conditions can be adapted to suit the requirements of tea plants, enabling them to be grown in colder areas of Australia, such as Zone 2. In colder climates, tea plants do best in large pots, which can be brought indoors during winter to ensure the tea roots are not damaged or killed by freezing winter temperatures. While established tea plants will tolerate light frosts, the timing of the frost may damage developing leaf buds, hence the preventative methods employed on frost susceptible tea plantations in Kenya, Japan and Southern Australia.