A federal appeals court on Thursday ruled that the Trump administration could continue removing signs and exhibits about slavery, climate change and other fraught topics at national parks across the country, at least for now.

The decision reversed a lower court’s ruling that blocked the National Park Service from carrying out President Trump’s directive to remove all “negative” displays.

It was a temporary victory for Mr. Trump, who has sought to purge national parks, Smithsonian museums and other federal sites of what he has called “woke” ideology.

In practice, it means that the Park Service can continue deleting materials while the appeals court considers the legality of the president’s directive, an executive order titled “Restoring Truth and Sanity to American History.”

That executive order said that materials at national parks should not “inappropriately disparage Americans past or living.” It added that they should emphasize the “progress of the American people” and the “grandeur of the American landscape.”

To comply with the order so far, the Park Service has taken down plaques about slavery at Independence National Historical Park in Philadelphia, a sign about climate change at Fort Sumter in South Carolina and a sign about Indigenous people at Acadia National Park in Maine.

Last month, Judge Angel Kelley of the U.S. District Court for the District of Massachusetts prohibited further removals. Judge Kelley, a Biden appointee, also ordered the Park Service to restore within three weeks any exhibits that it had dismantled or altered.

In her ruling, Judge Kelley wrote that national parks could help educate visitors about difficult periods of American history, as well as contributions made by people of color, gay and transgender figures, women and other marginalized groups.

“From the echoes of abolition in John Brown’s Fort in Harpers Ferry, to the genesis of the modern L.G.B.T.Q.+ civil rights movement at the Stonewall National Monument, to the retreating ice of Glacier National Park,” the judge wrote, “the national parks preserve the multifaceted and multilayered history of our nation, including the good, the bad and the ugly.”

But in the unanimous decision on Thursday, a three-judge panel of the U.S. Court of Appeals for the First Circuit found that Mr. Trump’s directive was unlikely to cause “irreparable harm” to the plaintiffs, a coalition of advocacy groups including the National Parks Conservation Association and the Coalition to Protect America’s National Parks.

Chief Judge David J. Barron, an Obama appointee, wrote the decision. He was joined by Judge Julie Rikelman and Judge Gustavo A. Gelpí, both Biden appointees.

Brooke Menschel, a senior counsel at Democracy Forward, a legal group that represented the plaintiffs, said in a statement that the decision was a “temporary procedural setback.” The timing was regrettable, she said, given that removals were allowed to proceed “at the moment when so many Americans will be enjoying the parks over the upcoming semiquincentennial weekend.”

Representatives for the Interior Department, the parent agency of the Park Service, did not immediately comment on the decision.

Mattathias Schwartz contributed reporting from Philadelphia.