Man charged over deliberate Tas bushfire

A man has been charged over a deliberately lit bushfire in northeast Tasmania, where a string of blazes have destroyed a home and burned more than 11,000 hectares.

The 35-year-old is accused of deliberately setting vegetation alight at Mangana on Monday when a total fire ban was in place.

He was due to face an after-hours session of the Launceston Magistrates Court on Saturday night.

Several "watch and act" alerts remain in place for the cluster of fires around Mangana, near the township of Fingal.

Conditions were milder than expected across the state on Saturday, but authorities are keeping close tabs on fires into the evening amid strong winds.

Bushfire smoke from raging blazes in Victoria blanketed Tasmania on Saturday morning, forcing authorities to issue a public health alert.

The air quality was at its worst in the island state's northern and central regions, and the smoke turned skies hazy over Hobart.

A cooler change brought relief in the afternoon and pushed bushfire smoke away from the island.