After weakening from a hurricane to a post-tropical cyclone early Saturday, Lee brought gusty winds, rain and dangerous surf conditions to coastal communities in New England, while the center of the much-anticipated storm moved toward an expected midday landfall near the U.S.-Canadian border.

By midmorning Saturday, it appeared that Cape Cod and coastal Massachusetts had been spared the devastating impacts once feared from what had been a major hurricane. But anxiety was climbing in far eastern portions of Maine, and in Atlantic Canada, where wind speeds and wave heights intensified as the storm closed in on Saturday morning.

Nearly 15,000 customers in Maine and 100,000 customers in Nova Scotia were without power early Saturday, according to Nova Scotia Power and poweroutage.us, a website that tracks utility data, and flight cancellations were multiplying at airports in Boston and Bangor and Portland, Maine.

“We haven’t seen the brunt of the storm yet,” said Carol Dennison, select board chairwoman in Lubec, Maine, a coastal town of 1,300 people at the Canadian border that contains the easternmost point in the continental United States. She said the town had no electricity and no internet service on Saturday morning as she headed to town hall with a generator. “High tide is at noon,” she added, “and that will be interesting.”

As Lee inched closer on Friday, Maine opened emergency shelters, residents in New England secured their boats ashore and Nova Scotia prepared for power outages and floods. Early Saturday, tropical-storm-force winds, which forecasters warned could down trees and knock out power, were occurring in Massachusetts and Nova Scotia, the National Hurricane Center said.

“Winds continue to be the biggest concern with Lee,” the National Weather Service office in Portland, Maine, said early Saturday.

Winds gusted to 44 miles per hour in Provincetown, at the outer edge of Cape Cod, and to 55 miles per hour on the island of Nantucket, 30 miles off the Massachusetts coast, and hit 77 miles per hour on Grand Manan Island in New Brunswick, Canada, according to the National Hurricane Center.

For almost two weeks, residents in eastern Canada and along the Eastern Seaboard of the United States have kept a wary eye on the slow-moving storm, which startled scientists earlier with how rapidly it had intensified and at one point led many people to worry that it could slam into the U.S. coast with devastating consequences.

“It has been a very long buildup,” said Todd Foisy, a meteorologist with the National Weather Service in Caribou, Maine. “But that’s good news for us because we could see it coming,” he added. “We had time to prepare.”

In recent days, the storm, which was once a Category 5 hurricane with 165 mile-per-hour winds, weakened as it moved over cooler, northern waters. Though scientists say it still could inflict heavy damage across a broad area of New England and the Canadian Maritime Provinces, forecasters no longer considered the storm a catastrophic threat and instead likened Lee to a forceful Nor’easter.

“While the storm may be weakening, it is still a significant storm,” John Lohr, a member of the Nova Scotia Legislature who is responsible for the province’s emergency management office, said in a news conference on Friday.

Ferries were docked and sports events canceled in Nova Scotia on Saturday. In Yarmouth, a town on the southwestern tip of the province where the storm was expected to make landfall, many shops and cafes on the main street were closed, said Cindy Nickerson, co-owner of a local clothing store, Yarmouth Wool Shoppe. Ms. Nickerson said the street lamps and streetlights were rattling in the wind.

“It’ll blow for a while. Then it’ll stop. Then it gets another huff,” she said.

Officials have advised residents of southwestern Nova Scotia, which appeared to be directly in the storm’s path, to stock up on food and water — and to keep cars away from trees, which may be felled by high winds.

Compared with the intense storms that tend to hit the southern half of the United States, Lee has moved more slowly — and become more sprawling. Its gusting winds will not break speed records but could still cause hazardous storm surge and power outages.

In a region that is used to winter Nor’easters, this late summer storm brings a different set of challenges. Coastal flood warnings have forced some seaside businesses to batten the hatches during the tourist season, though some towns were already empty of tourists. And the trees in the storm’s path may be more likely to fall at this time of year because their branches are heavy with leaves and the soil is looser, and that in turn could knock down power lines.

Maine declared a state of emergency on Thursday, and President Biden authorized a federal emergency declaration. The governor, Janet Mills, warned residents that the high winds “likely will cause storm surge, inland flooding, infrastructure damage and power outages.”

Massachusetts also declared a state of emergency on Friday. There and elsewhere along the coast of New England, the most visible signs of preparation were the various boats being hauled up from the water. The storm passed east of Cape Cod, which was under a coastal flood warning on Saturday morning, bringing strong winds but few reports of damage, an outcome that left many grateful for having dodged a bullet.

In Orleans and Harwich, a few trees fell and blocked side roads, the police said, while the authorities in the town of Truro did not have a single call about the storm overnight on Friday.

“We’ve been very fortunate,” said a police dispatcher in Chatham, another small town on the outer Cape that had braced for the worst.

Still, public safety officials warned that rip currents and high surf would remain dangerous even on Sunday, when the sun would re-emerge, and urged beachgoers and wave watchers to be cautious. “Do not risk getting swept out to sea,” read a notice on the website of the Cape Cod National Seashore, which closed some beach access points.

The storm forced cancellations across the Cape — of charity bike rides, youth soccer games and outdoor weddings, on a favored fall wedding weekend — but there was also perseverance in the face of nature’s wrath.

After her friends flew in from around the country to celebrate her birthday, Maci Palumbo forged ahead with a beach picnic party in Harwich on Friday evening, despite blustery winds that tossed their hair and threatened to blow sand onto her heart-shaped cake.

“The hurricane doesn’t stop this!” Ms. Palumbo’s friend Hannah Marson, 23, shouted over the wind as several young women tried to shield the pink confection.

Alexandra Lee and Kyle Johnston, both 27, may have demonstrated even more pluck, persisting with their Cape Cod wedding weekend with the help of venue staff who found indoor spaces to replace the outdoor ones they had planned to use.

“We’re feeling good,” Ms. Lee said Friday evening at a cheese-tasting party in Chatham before heading to a rehearsal dinner at a Truro vineyard. “The way I put it is, we’ve gone through all the stages of grief, to full acceptance.”

In Lubec, residents are used to bad weather, usually in the form of cold and windy winters, said Victor Trafford, the owner of the Inn on the Wharf, which looks out over Johnson Bay.

“We’re high enough above the ocean,” Mr. Trafford, 66, said on Friday. “I expect to be OK.”

John Yoon, Alicia Anstead, Colleen Cronin and Meagan Campbell contributed reporting.