HANOVER — More than 4,600 Grafton County electricity customers lost power for about an hour and a half midday Monday, causing businesses to close and Dartmouth Hitchcock Medical Center to cancel appointments.

High winds on Sunday blew a tree onto power lines near Centerra Marketplace on Route 120, Lebanon Fire Chief James Wheatley said. Monday’s power outage happened while crews cleared the tree from the lines around 11 a.m., Wheatley said.

Downtown Hanover and the Route 120 corridor in both Hanover and Lebanon were among the areas affected by the outage.

When the power went out, DHMC canceled all appointments and closed its child care center, sending children home for the day.

However, by 1 p.m. once electricity was restored, the hospital announced “patients who had scheduled appointments or procedures for the remainder of the day should come in as planned.” The child care center remained closed, since all of the children had already gone home, DH spokesperson Cassidy Smith said.

Several downtown Hanover businesses locked their doors and taped homemade signs to their windows telling customers they were closed due to the outage.

“This is unprecedented,” Nick Porcello, a sales manager at Pompanoosuc Mills, said while lounging in the dark on one of the furniture store’s couches.

Porcello, a longtime Upper Valley resident, was impressed with how drivers handled the traffic lights being out before police arrived to direct traffic. “People were being kind and courteous to one another,” he said.

The outage disrupted the schedules of several Dartmouth students who didn’t know where to go to find internet access or a bite to eat.

“We’ve been walking around for almost 30 minutes,” Abby Dollries, a graduate student at Dartmouth, said of herself and two friends.

When the roommates lost power in their off-campus home in Lebanon, they decided to come to Hanover to find a place to study.

“We hoped the town would have power,” Dollries said.

Maddie LaFata, a sophomore at Dartmouth, was in psychology class when the power went out. The darkness was short-lived because the college’s generators kicked in.

“It flickered then came right back on,” she said.

LaFata had ordered lunch online from Molly’s Restaurant and Bar, but when she arrived to pick up her food, the door was locked and the lights were off.

“My friend’s on the phone with them now trying to figure it out,” she said while standing outside of the restaurant on South Main Street.

Once the power came back on at around 12:30 p.m., employees scrambled to reopen businesses.

Although the ice cream shop, Hanover Scoops, isn’t usually open on Mondays, the store made a special exception for Dartmouth’s accepted students day.

“We were supposed to open at noon,” employee Janiely Vazquez said at almost 1 p.m. “I’m trying to set things up so we can open now.”

While Vazquez said the ice cream seemed fine, one of the soft serve machines was making a sustained beeping noise she didn’t know how to shut off, preventing her from unlocking the door to customers.

Tali Lissner was visiting from Illinois with her daughter, who was among the recently accepted students visiting Hanover on Monday. Lissner said the outage didn’t affect her morning in Hanover.

“Everyone’s handling it well,” she said, while grabbing lunch at The Works Cafe after the power went back on.

Emma Roth-Wells can be reached at erothwells@vnews.com or 603-727-3242.