The salt lake in Westgate Park, in Port Melbourne below the Westgate Bridge, has turned bright pink due to a perfect mix of high temperatures, sunlight and low rainfall.

The lake often turns a red pigment in the warmer months before turning to its usual blue in autumn.

"Algae growing in the salt crust at the bottom of the lake produces the red pigment (beta carotene) as part of its photosynthesis process and in response to the extremely high salt levels," Parks Victoria said on Facebook.

The organisation encouraged people to "enjoy the views", but warned not to touch the water.

It said the lake was expected to return to blue when the weather cooled down and rainfall increased.