Kaikoura High School could not open for the first day of term two yesterday because power cuts meant there was no heating.
Lighting struck the Mainpower substation on Ludstone Rd, near the high school, shortly before midnight on Sunday, and struck three transformers in Ward St and Avoca St shortly after.
Mainpower crews restored power to most homes within a couple of hours but Kaikoura High School, and the Kaikoura District Council building on the Esplanade, did not have electricity yesterday morning.
Kaikoura High School principal Werner van Aswegen said staff contacted students shortly before 7am to let them know the school would be closed as the heating system was not working.
Schools are legally required to have heating available for students. Only three of the school's 240 students missed the message and were waiting for a ride back home at 9am.
School was to resume today.
The last time the weather closed the school was during three days of snow in August, 2011.
Mainpower engineering manager Peter Hurford said: "I've never heard about a lightning storm this strong in Kaikoura.
"It usually skirts around the foothills. Probably the worst area is Oxford, by Cheviot [south of Kaikoura]."
- The Marlborough Express