OLYMPIA — Gov. Jay Inslee is extending his “Stay Home, Stay Healthy” order until May 31, he announced during a news conference Friday.

Data show that social distancing is working in the state’s fight against the novel coronavirus, but it’s too early to ease restrictions, Inslee said. In recent weeks, some construction has resumed and outdoor recreation sites have been reopened, but Inslee and local leaders are pleading with residents to continue practicing social distancing to prevent the disease from re-surging.

“We have not won the fight with this virus,” Inslee said. “I would like to tell you that we could all make reservations for June 1, but I cannot. We will have to monitor, assess and adapt.”

The governor also unveiled a four-phased plan to reopen the state. There will be at least three weeks between phases, Inslee said.

• In coming weeks, retail stores will be allowed to offer curbside pickup. Additionally, restrictions will loosen for landscaping, auto sales, home cleaning and pet walking businesses. Phase one also includes drive-in worship services.

• The next stage would allow camping, gatherings with no more than five people outside a household per week, new construction and limited non-essential travel, as well as open retail stores, hair and nail salons and restaurants at 50% dine-in capacity.

• The third phase would allow recreational sports with five to 50 people, gatherings of fewer than 50 people, all non-essential travel and open facilities like public pools, libraries and museums. Restaurants could operate at 75% dine-in capacity, bars at 25% and indoor gyms and movie theaters at 50%.

• The final stage would allow gatherings of more than 50 people and open nightclubs, concert venues and large sporting events. That could occur by mid-July, Inslee said. But a spike in cases, hospitalizations or deaths could cause the governor to renew restrictions.

“The success would be to only have to go through this once,” he said.

Smaller, rural counties that might not be as affected by the virus as others can apply to the state Department of Health to skip ahead to the next phase.

Also on Friday, Snohomish County leaders asked residents to continue social distancing as county and some city parks open and other restrictions loosen starting Tuesday.

“If we don’t do it wisely on an individual and a mass level, we’re going to see a resurgence of cases,” said Dr. Chris Spitters, health officer for the Snohomish Health District, said at a news conference. “We really need everyone’s help to socially distance themselves while doing these activities and try to maintain the difficult and painful discipline you’ve been showing over the past few months.”

As of Friday, the Snohomish Health District reported 2,467 confirmed coronavirus cases, with at least 109 deaths. Nearly 1,700 county patients have recovered. Statewide, there were 14,327 confirmed cases as of Thursday, with at least 814 deaths, the state Department of Health said.

In recent weeks, there have been about 30 new confirmed cases each day on average, down from about 100 per day a month ago. The flattening of the curve is an improvement, but it could be better, Spitters said.

“Certainly my hope and my colleagues’ hope is that we could get to a little bit lower baseline,” he said.

The number of new cases throughout the county has primarily been coming from long-term care homes, health care workers and clusters in families and small social groups, Spitters said.

The health district has tested more than 800 residents and staff across eight long-term care homes, Spitters said. Results came back positive for 16% of residents and 9% of staff.

“We want to get everyone tested when there’s a cluster,” he said.

Spitters is also worried people aren’t going to hospitals out of fear they could come in contact with the virus. Hospital staff have plans for separating possible COVID-19 patients from people with other health problems, he said. Delaying medical attention will likely worsen a condition.

If you’re worried about visiting a hospital, call ahead.

Back in Olympia, Inslee, along with health experts, said reopening the state will require widespread testing and contact tracing — determining who has come in contact with infected people so they can self-quarantine.

The federal government has promised enough test kits to quadruple the state’s supply, Inslee said.

The governor and the health district are strongly recommending residents wear cloth face masks when they’re out. There’s no plan to require masks, but it’s an option.

Snohomish County residents shouldn’t expect anything close to normal for a while, County Executive Dave Somers said at the county’s news conference.

“Until there is a vaccine and effective treatment, we’re going to have to take extra precautions for the foreseeable future,” Somers said.

It could take a year to 18 months to develop a vaccine, health experts have reported. And a widely effective treatment hasn’t been found.

At Providence Regional Medical Center Everett, doctors are engaging in a trial for a drug called Remdesivir. So far, results have shown the treatment can shorten the duration of the illness by about three days, on average, Spitters said. The drug hasn’t shown a significant effect on lowering the number of deaths from the virus.

“This is not a magic cure for this,” he said. “But it might mitigate disease in some folks. It’s a step in the right direction. As Dr. (Anthony) Fauci said, it’s proof of concept that this drug, or a relative of it, can ultimately have a role in treatment of COVID-19.”

Also on Friday, the Snohomish Health District was administering tests for the final day of its pop-up drive-thru test site in Lynnwood. The health district is expected to announce Friday afternoon a new location for drive-thru testing, either in north or east Snohomish County.

On Wednesday, 42 people visited the Lynnwood health district office and were given rapid coronavirus tests, with results in 15 minutes thanks to new machines from Abbott Laboratories. All but one of those tests came back negative. Technical problems affected the other test. To study how accurate the Abbott tests were, all of the patients were also given a second test which was sent to the state’s public health lab.

Fifty more tests were scheduled for patients Friday.

This week marked 100 days since the country’s first case of COVID-19 — a man who was treated at Providence Regional Medical Center Everett.

“It seems like three years ago, frankly,” Somers said.

Joey Thompson: 425-339-3449; jthompson@heraldnet.com. Twitter: @byjoeythompson.