Bureau of Meteorology data released on Thursday revealed the first month of 2018 in Tasmania's capital was the equal warmest in 122 years of comparable records.

The mean temperature for January was 19.3C level with 2003.

"Often in Tasmania, even in summer, you get a mixture of cold and warm weather but we got very little in the way of cold," BoM forecaster Ian Barnes-Keoghan said.

"Australia as a whole was quite warm, so we copped a bit of that."

An Australia Day long weekend heatwave, where the mercury in Hobart reached 36C on Sunday, pushed overall figures into record territory.

The 28th was the hottest day in the Apple Isle capital for four years.

Hobart's hottest January night followed, with the overnight temperature not dropping below 23.9C.

Rainfall was below average in the western half of Tasmania.

A warmer-than-average February was expected across the state, Mr Barnes-Keoghan said.