Tasmania is the outlier in every Australian generalisation. It is cold, it is mountainous, its weather turns in an afternoon, and its racing calendar runs when the mainland's cannot.
Verus currently lists 75 running races in Tasmania — 7 marathons, 9 half marathons, 14 10Ks, 13 5Ks, 10 ultras and 22 at other distances — alongside 24 weekly parkruns and 1 multisport event. Those counts come from the data on this site rather than from a claim about it, and they move as the calendar does.
A climate the rest of the country does not have
Hobart's hottest dawn, in January, averages 14.5°C at a 10.7° dew point — cooler than a Sydney April morning and comfortably inside the no-penalty band. Its July dawn is 5.8°C. In eleven years of records not one morning reached 24°C, and neither did Melbourne's, but Tasmania is a further five degrees colder across the board.
That is why the Cadbury Marathon runs on 3 January, in the middle of an Australian summer, and why Tasmanian parkruns start at 9:00am rather than the 7:00 or 8:00 used everywhere else — the mornings are dark and cold rather than hot.
Hobart
The Derwent runs through the city and kunanyi/Mount Wellington rises 1,271m directly behind it, which gives Hobart a vertical range no other Australian capital comes close to. The Pipeline Track and the Organ Pipes give real mountain trail twenty minutes from the CBD; the summit road is a sustained road climb; and the Intercity Cycleway gives flat, traffic-free running along the river to Glenorchy.
The Cadbury Marathon on 3 January runs from Claremont with distances from 1km to the full marathon. Run the Bridge in February crosses the Tasman Bridge on closed road, and the Hobart Marathon Festival adds an April date.
Launceston and the north
Launceston has the Cataract Gorge on its doorstep — a genuine gorge with trails on both sides, minutes from the city centre — and its own running festival in May with a half marathon, 10km, 5km and a mile. The north coast around Devonport, Burnie and Wynyard carries a dense club calendar for a population that small.
The wilderness
The centre and west of the island are the most alpine-feeling running in Australia. Cradle Mountain, the Overland Track, the Walls of Jerusalem and Mount Field give terrain that genuinely resembles New Zealand or Scotland more than mainland Australia, and the weather to match — snow is possible in any month above about 1,000m.
Freycinet on the east coast, the Three Capes on the Tasman Peninsula and Maria Island add coastal trail. Flinders Island, in Bass Strait, holds its own running festival.
What to respect
Tasmanian mountain weather is the one genuine hazard in Australian running that resembles the British hills: cold, wet, windy, and capable of changing inside an hour. Hypothermia is a real risk on the plateau in any season, and it is the reason Tasmanian trail events carry mandatory gear lists that look more like a Scottish race than a Queensland one.
When to run
Any time at sea level; November to April in the mountains. November is the wettest month at 12.6 rain days, and even midsummer needs a windproof layer on the tops.