The average maximum summer temperature in Tasmania is 22 to 24 degrees C (72 to 76 F).  The average maximum winter temperatures are 11 to 13 C (52 to 56F).  Average winter minimums are above freezing in coastal areas, and a few degrees below freezing at higher altitudes.

The main tourist season extends from October to early May, although the weather is not so harsh as to preclude touring all year round. 

Tasmania has a distinct Spring flush of flowers and new growth, while in Summer, when temperatures and humidity on the Australian mainland can be very uncomfortable, Tasmania is at its best.

Weather in Autumn and Winter is driven by the prevailing westerly weather streams – the Roaring Forties.  So the weather can be more sheltered on the East Coast than on the West Coast.  Snow persists on the higher mountains, including Ben Lomond, Mount Wellington and the Central Plateau.  Snow flurries are not uncommon anywhere on the central plateau, even in the warmer months.

Wherever you travel in Tasmania, you should be prepared for rapid, temporary deteriorations in weather, especially if bushwalking.  Additional warm clothing, including a waterproof outer layer, should always be carried.

Climate data for Hobart (in the south of the state) is here.

Launceston, in the north, is a few degrees warmer in summer and slightly colder in winter.

Current weather observations for Hobart are here.