Thousands of households and businesses remained without power in New Brunswick and Nova Scotia.
Most of the outages were in New Brunswick, where fewer than 10,000 customers were without power as of Saturday night.
NB Power spokesman Bob Scott said the utility hoped to have most customers in the province reconnected on Sunday.
"We're certainly heading in the proper direction," he said, adding that 315 crews were on the ground.
"The most important thing of all is that we're doing this in a very safe manner because that's the way it has to be done."
More than half of the outages were in and around the capital city of Fredericton. The city has said more than 4,000 trees were damaged or downed by the storm, not including trees in city parks or on private property.
"There are a lot of huge trees down in Fredericton," said Scott. "Trees falling on trees ... falling on lines, all tangled up and in backlots in some cases."
The province's Emergency Measures Organization issued a statement Saturday urging people to stay away from trees damaged by the storm. The organization said there were reports of people playing in trees entangled in power lines or using power saws to cut trees.
"These activities are extremely dangerous," it said. "Lines can be hidden in downed trees and they still may be energized."
In Nova Scotia, the number of customers without power had dwindled to a handful by late Saturday.
She said it could be late Sunday before power is restored to a handful of isolated properties, mostly cottages.
Premier Stephen McNeil said Friday that Nova Scotia Power's response to post-tropical storm Arthur was "inexcusable."
He said the province's Utility and Review Board will look into how the utility responded to the outages, including storm preparedness, its staffing levels, vegetation management, communications and the state of transmission and distribution infrastructure.
Earlier this week, Nova Scotia Power CEO Bob Hanf apologized for problems the company had communicating estimated restoration times to its customers through its website and call centre.
Hanf issued a statement Friday welcoming the review.
"We always review our performance after every significant storm and look for lessons we can learn to perform better," he said. "With a major storm like Arthur, a review process with the Utility and Review Board is appropriate, given the impact of the storm and the number of Nova Scotians who were affected."
Arthur knocked out power to more than 250,000 customers at the height of the storm.