Gov. Charlie Baker announced Thursday that museums, gyms and movie theatres would be allowed to restart business on Monday as part of the third phase of the state’s gradual reopening plan — even as Covid-19 case numbers surge nationally and other states reverse course.

In his daily press briefing, the governor said public health metrics in the state remained positive, with hospitalizations, the percentage of daily positive cases and deaths all flatlining or decreasing.

“Today the public health data makes clear that Massachusetts is effectively bringing the fight to the virus as we’ve reopened,” the governor said. “And thanks to all your efforts, phase three will begin here in Massachusetts on July 6.”

According to regulations posted by the Baker administration, phase three will allow movie theaters, outdoor performance venues, museums, cultural sites, fitness centers and health clubs to reopen. Sports teams, without spectators, will be able to hold games as well.

The governor also adjusted the guidelines for gatherings as the Fourth of July weekend approaches. Indoor gatherings are now limited to eight people per 1,000 square feet or 25 people in a single enclosed space. Outdoor gatherings are limited to 25 per cent of the facility’s maximum capacity, topping out at 100 people. Backyards and parks do not apply.

The new guidelines and institution of phase three comes as Covid-19 cases skyrocket across the country and other states, including New York, have backed off reopening plans.

On Thursday, Gov. Baker said that Massachusetts residents had shown that they were capable of fully complying with regulations, allowing the state to continue to reopen.

“The people in Mass have demonstrated, time and time again, that they are willing to comply fully with the guidance and protocols associated with maintaining a safe operation across these couple of months,” the governor said.

Bars and nightclubs, which are part of phase four, will remain closed for the foreseeable future, the governor said. He said that phase three, like phase two, would have multiple parts, and that phase four would not come until therapeutics or vaccines were widely available.

“This phase will last significantly longer than our other phases so that we can closely monitor the impact to our public health data that comes with this move to phase three,” the governor said. “The primary driver in much of the significant increase in positive tests in a number of tests has been the reopening of bars and nightclubs. And obviously bars and nightclubs are sitting in phase four under our guidance. And there’s a reason for that.”

On the Vineyard, facilities like the Martha’s Vineyard Film Center and the YMCA have been offering virtual movie screenings and fitness classes, waiting for the go-ahead from the state to reopen. The Martha’s Vineyard Museum has announced that its outdoor campus would reopen on July 3 to the public, and has also been offering virtual services.

Previous phases of the governor’s reopening plan have allowed restaurants to provide outdoor dining with restrictions and severely limited forms of indoor dining. The governor said that allowing larger indoor facilities as part of phase three heightened the risk of spreading the virus, explaining that phase four would be a long way off.

Governor Baker also provided advice for residents looking to celebrate the Fourth of July holiday.

“I ask you to keep in mind the things you have been doing to stop the spread. I would just ask that you continue to be smart about how you make your backyard barbecue an enjoyable and safe event,” the governor said. “I believe we will get through this together.”