Work is ongoing on Saaremaa to fix power lines damaged by Monday's storm. Repairs have been completed on Hiiumaa.
As of 8 p.m., 479 customers were still without power on Estonia's biggest island, Elektrilevi's live map showed.
Major work is ongoing in Järis, Võhma and Pank regions and new problems may be reported elsewhere, Elektrilevi's communications and marketing manager Kristi Reiland said. Some households will not regain their connection today.
Over 40 teams, made up of 100 people, are still working in Saaremaa, alongside volunteers.
Mihkel Härm, Elektrilevi's board chairman, said the situation is different in neighboring Hiiumaa: "We have managed to eliminate all storm breakdowns and restore electricity connections to customers."
He added problems in Saaremaas should be fixed by the weekend.
"We have mapped the breakdown locations with drones and we hope to fix all the main medium voltage breakdowns by Friday evening," he said.
Heavy snow and ice caused tree branches to fall on powerlines, but Elektrilevi requests that people do not touch broken wires. Instead, they can be reported on the MARU app.
Several hundred people were left without power on Saaremaa on Saturday after a storm. The situation worsened after Monday's blizzard.
Some areas of Saaremaa have been without power since Saturday, assistant mayor of Saaremaa municipality Liis Lepik told ETV's "Ringvaade" on Thursday. There are also problems with the mobile network.
On Thursday afternoon, ERR reported that more than 1,200 households were still without power.
Editor: Aleksander Krjukov, Helen Wright