A lightning strike at a Hamilton School caused emergency services to be called out to check on staff who may have been affected.

Students at a Hamilton school struck by lightning were playing near the scorched site only an hour earlier.

The lightning struck rugby goalposts at Hamilton Junior High School about 1.30pm Monday before travelling along a set of classroom buildings at the adjacent Hamilton North School.

Hamilton Junior High School acting principal Rebecca Hodgson saw the lightning hit the goalposts from her office windows and said the sound was "incredible".

DOMINICO ZAPATA/STUFF Emergency services at Hamilton Junior High School and Hamilton North School following a lightning strike in the suburb of Saint Andrews.

"Our students were inside at the time thankfully and we made sure to keep them away from the windows because our buildings have aluminium joinery," Hodgson said.

"An hour earlier we had students playing outside and we would have had some around the goalposts. They would have all been out on the courts."

"When the lightning hit the posts there was a big explosion and everyone got a fright. It was random and luckily no kids were outside."

Four ambulances and a police car were parked at the grounds of Hamilton North School on Warwick Ave shortly after 2pm.

A St John spokesperson confirmed they had responded to a lightning strike at the school grounds. St John had initially reported three patients, she said.

None were seriously injured and they were all adults.

A Waikato Hospital spokeswoman said the four adults were being assessed in the emergency department.

All four were in a stable condition.

Hamilton North School principal Tony Kane said

the bolt ran straight along the structure after hitting the post.

"If you look around the goal posts, you can see all these holes around it," Kane said.

Four staff members were left feeling "shaken and tingly" and were taken to hospital for precautionary checks.

The school caters to special needs students. Kane said it was difficult to tell whether any of the students were similarly affected so paramedics were asked to conduct a group check.

Ambulance and police responded quickly to the scene, he said.

MetService duty forecaster Heath Gullery said there were 72 lightning strikes across the Waikato before 3pm.

More thunderstorms were expected across the Waikato on Monday afternoon before easing during the evening.

A front will bring further thunderstorms on Tuesday morning, too.



Gullery said although it wasn't an unusual amount of lightning strikes, it was rare for people to be injured.



"Lightning generally tries to find a higher point to connect with, be it a goalpost or top of a building," Gullery said.



"It doesn't necessarily seek out a goal post or anything, it was just bad luck it hit the school."



He said it would be unusual for a bolt of lightning to hit the goalpost and then the school building and thought it may have been a separate bolt that injured the adults.



"Lightening strikes are so unpredictable. If thunderstorms are around, be aware of the weather and be indoors if you can."

A Warwick Ave resident, who declined to be named, said there was a large flash of exceptionally bright, blue-coloured lightning just before 1.30pm.

"It was a loud cracking sound. It sounded like a gunshot.

"I have just never experienced anything like it," the resident said.

Residents Anne and Alan Pellow were sitting down for lunch about 1.30pm when the sky darkened.

There was a "hell of a loud" sound, Anne said. Then the lightning struck.

"There's always a bit of noise coming from the school but you get used to it. But there's been a lot of noise and wailing coming from the school this afternoon," Anne Pellow said.

"Clearly some of the students are very upset."

After the incident, some school staff could be seen hugging and consoling each other in the light rain.

The strike happened amid an afternoon of thunderstorms across Hamilton.

Kane and Hodgson said their schools practise for a range of incidents but not lightning strikes.