Tasmania reported 1700 new cases on Wednesday, the highest figure since April 20, while active infections were above 8000 for the first time since late April.
Mask mandates were dropped for remaining indoor venues on July 1, but businesses and organisations may require staff or patrons to wear them as part of workplace health and safety practices.
The surge in cases across Australia is being driven by two Omicron sub-variants, BA.4 and BA.5.
"This wave is occurring nationally, in line with the cooler months of winter and the fact people tend to be socialising more indoors," Premier Jeremy Rockliff told reporters.
"It is important to take personal responsibility. This means staying up-to-date with vaccines and choosing to wear a mask when it's not easy to socially distance.
"In fact, in the current circumstances with rising case numbers, I would strongly recommend the wearing of masks in indoor public spaces."
State Public Health Director Mark Veitch said case numbers would remain high for the next month or so.
"The risk level is quite high, there's a lot of COVID around. If you've got measures you're contemplating using to control the risk personally, or in your workplace, now is the time to use it," he said.
Dr Veitch didn't rule out reintroducing public health measures if new strains spread.
"If we were to see an emerging threat ... for example a strain of COVID that was much more virulent, of course we would look to what measures need to be put in place to address that," he said.
Tasmania recorded one additional death on Wednesday. There are 79 people with the virus in hospital, including two in intensive care.
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