 Tasmania has an oceanic temperate climate characterised by cool summer and mild winters , with a small maximum temperature variation during the year . <unk> lies in the rain shadow of the Great Western Tiers ; rainfall in parts of the tiers exceeds 2 @,@ 000 millimetres ( 79 in ) . Since the 1950s average temperatures in the surrounding Meander Valley have steadily risen and since the 1970s average rainfall has declined . 
