Tasmania has extended its free flu vaccination program for a month amid a winter spike in infections.

The state government on Monday announced the roll-out at GPs, pharmacies and state-run clinics will continue until July 31.

"As expected, after two years of very few cases in Tasmania, influenza is re-emerging in the state," Premier and Health Minister Jeremy Rockliff said in a statement.

A record near 250,000 people in Tasmania have received a flu shot, but a quarter of the over-65 population is yet to get a jab.

"Additionally, we are focused on increasing the rates of children aged between six months and five years with only 26.8 per cent having received a vaccine," Mr Rockliff said.

The health department has been notified of 1670 cases of influenza this year.

New flu cases, reported each week, have tracked 232, 324, 381, 487 across the month of June.

"People may consider wearing a mask to offer them further protection when they are in more crowded places and cannot maintain physical distance," Mr Rockliff said.

"Everyone with respiratory symptoms is reminded how important it is to stay at home until their symptoms clear."

GPs and state-run clinics provide vaccines for people six months and over; and participating pharmacies for those aged 10 and over.