1 The annual mean temperature in Hobart, Tasmania, Australia is mild at 12.9 degrees Celsius (55.1 degrees Fahrenheit).2  Average monthly temperatures vary by 8.9 C (16 F) which is a very low range.obart, Tasmania Average Temperatures Chart. The average temperature charts use a fixed scale so that you can easily compare temperatures between two or more locations. Simply line up the charts in separate tabs in your browser and toggle between tabs to visualise the differences.