A man in his 20s has died after being struck by lightning while camping on top of Mount Warning, in northern New South Wales.

Emergency services were called to reports of injured campers on the mountain near Murwillumbah about 4.50am AEDT today.

Commander of Police at Tweed Byron Local Area Command, Superintendent Wayne Starling, said two campers had pitched their tent to a tree, which had been struck by lightning.

The strike travelled through the man’s feet.

Police say the man’s female companion, also in her 20s, was also struck and was taken to Murwillumbah Hospital with neck injuries.

Supt Starling confirmed the two hikers were tourists and said another group of hikers came across the scene of the incident before emergency services.

Two Queensland teens attempted to resuscitate the man but police say he would have died instantly.

A rescue crew made up of about 15 people trekked to the summit to rescue the group and retrieve the victim’s body.

Rescue crews trekked to the lightning strike scene. (9NEWS)

Supt Starling described the incident as a "tragedy" and said the incident was "very unusual".

Nearby residents said the area was hit by an "incredible" thunder and lightning storm overnight.

The fatal strike follows wild weather across the state yesterday, which saw 9000 bolts of lightning pummel the city in just four hours.

At Church Point, a man survived being struck by lightning on a yacht off Sydney's northern beaches.

A man died after being struck by lightning on Mount Warning. (9NEWS)

Another strike sparked a house fire in Huntleys Cove, devastating the home. A mother and her two daughters managed to escape the blaze.

"There was this most incredible noise and explosion, the like of which I've never heard before," a neighbour told 9NEWS.

The NSW SES received more than 200 calls for help last night, mostly for leaking roofs and fallen trees.

The Bureau of Meteorology has advised that the immediate threat of severe thunderstorms has passed.

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