Hundreds of properties on St Mary's have suffered power cuts today, the second of which is still ongoing.
The first outage, which started at 7.46am, prompted the school to close for the day, forcing some parents to take time off work to look after younger children.
The gym and sports hall at Carn Gwaval are also closed and will remain so for the rest of the day. They are expected to be open as normal tomorrow. The Council posted on its website: "Power is still down on the site which is affecting telephone lines, showers, lighting and the gym equipment. The decision has therefore been taken to close the site.
"We apologise for the inconvenience and we anticipate the site being open tomorrow as normal. In the meantime, if you need to make payments to the council, you can do this at the Town Hall."
The swimming pool at Normandy has also reported that its power is down.
The Airport is unaffected by the power cut but flights have been cancelled due to the weather.
Western Power told This is Scilly: "At about 7.46am, 277 customers were affected because we had some conductors down. By 8.37, we managed to restore everyone bar five customers. These were where we had to restring the conductors. They were all restored by 1.55pm.
"Unfortunately at 3.30pm, we had a second fault affecting some of the same people, 140 customers. They are still off at the moment. We are doing repairs at the moment and they will be back on as soon as possible."
A total of 853 homes were also left without power in the Cornish village of Fraddon this morning, reportedly due to a suspected cable fault.