Western Australia will reopen its borders from March 3 amid a growing Omicron outbreak, bringing to an end almost 700 days of seclusion.

Insisting the new date was "locked in", Premier Mark McGowan on Friday expressed confidence WA was ready to welcome back travellers given its high vaccination rates.

He acknowledged there was no prospect of stopping an outbreak which now numbers 794 active cases.

"Eventually there comes a point where the border is ineffective when you get to high case numbers within the state," he told reporters.

"It is plain to see that four weeks of caution has paid dividends. It means it is now far safer to relax our hard border settings."

Once the borders reopen, interstate travellers who are fully-vaccinated - including a third dose if eligible - will be able to travel to WA without quarantining.

Unvaccinated interstate travellers will remain locked out.

All international travellers will be allowed back in, but those who are unvaccinated must spend seven days in hotel quarantine.

The number of unvaccinated overseas arrivals will be limited to 70 per week.

Health Minister Amber-Jade Sanderson said modelling suggested WA's caseload would peak at the end of March at around 10,000 daily infections.

WA is expected to reach "peak immunity" that month but four lives are expected to be lost each day once the peak is reached.

WA Health on Friday recorded 194 local cases, taking the tally over the past three days to 486 new infections.

WA had 79 active cases and a third-dose vaccination rate of 26 per cent on January 20 when the premier announced the planned February 5 reopening would be indefinitely delayed.

More than 55 per cent of eligible West Australians have now received their booster, while the vaccination rate for children aged 5 to 11 has tripled to 45 per cent.

Mr McGowan insisted his decision had been vindicated because cases and hospitalisations elsewhere in Australia had since fallen significantly.

"If I had my time again, I'd do exactly the same thing," he said.

The premier added there was no prospect he would again backflip on the reopening.

"This date is locked in and I can't foresee a situation where it would change. It's only 12 days away so it's a lot closer than last time," he said.

The state will introduce tougher public health measures from Monday including extending the wearing of masks at indoor venues across the state.

"Level one" measures will come into effect in Perth, Peel, the South West, Wheatbelt, Great Southern and Pilbara regions, including a one person per two square metres rule at hospitality and entertainment venues, gyms, beauty services and places of worship.

Home gatherings will be capped at 30 people and private outdoor events in non-home settings to 200 people.

Visitor limits will come into effect at hospitals and aged care venues, but people won't be required to work from home.

People will no longer have to show proof of vaccination to purchase from bottleshops, with the requirement for other venues to also be reviewed.

Restrictions will be tightened further once case numbers grow significantly, including requiring children in year three and above to wear face masks.

Mr McGowan said he was hopeful the reopening would attract airlines back to Perth, including direct international flights.

Business Council of Australia chief executive Jennifer Westacott welcomed the "sensible" decision which she said would assist Australia's pandemic recovery.

The move was also praised by WA's Chamber of Commerce and Industry and the Australian Hotels Association, which urged the government to limit the duration of venue density limits.

Australian Medical Association WA president Mark Duncan-Smith said the new restrictions were appropriate and measured to help flatten the curve.