WATCH: Unsuspecting Beachgoer Wiped Out By Rogue Surfboard

A camera switched on at just the right time at Cronulla Beach has captured the exact moment an out-of-control surfboard slammed into a beachgoer.

The incident is believed to have occurred on Thursday afternoon just as wild winds began lashing Sydney, following a scorching day across NSW.

The video posted to Facebook has now been viewed thousands of times and shows the board knocking down the unsuspecting beachgoer from behind as they walked close to the water.

A number of people can be seen running towards the person to help as the board continued flying out of control down the beach.

Others in the video can be seen running away from the sand as the wild winds swept through the beach.

Temperatures on Thursday neared 40 degrees in the city and passed the mark in the west, officially becoming our hottest day of the year so far.

The scorching temperatures even resulted in a massive hour-long power outage to nearly 45,000 homes and businesses in Sydney's east.

READ MORE: Power Returns After Sydney Outage Hits 45,000

But just before 5pm the southerly came through, dropping temperatures by almost 15 degrees in just a few minutes.

READ MORE: Phew! After Hottest Day Of The Year, Sydneysiders Celebrate the Southerly

It is unclear who the person in the video was or whether they were seriously injured, but it's a reminder to everyone to stay safe with wild weather sure to return.