Flinders Island airport broke the three-decade-old record, reaching 41.5 degrees just before 4pm today [01.30].
The previous high was 40.8 degrees, set in Hobart in 1976.
Tasmanian temperatures have been well above average.
Launceston Airport reached 37.2 degrees, making it the hottest day there since World War II.
In the north-west, Marrawah recorded 33 degrees, while at Fingal in the north-east the temperature hit 40.6 degrees.