The presence of the trees shield the nearby area from the harsh sunlight and also slightly cool their surroundings by drawing in moisture from the ground.

And they have their work cut out for them. University of Melbourne Clean Air and Urban Landscape research fellow David Kendal said the average temperature of the city has risen 2 degrees in the past 50 years, driven by a combination of climate change and increased development.

As more buildings pop up, they trap heat during the day that takes longer to dissipate at night, creating a "heat island" effect that makes cities warmer than surrounding areas.

Dr Kendal said climate change projections predict the city's average temperature will rise a further 3.5 degrees by the end of the century, further intensifying the heat island effect.

But he said analysis of City of Melbourne tree canopy data show our trees are not equipped to deal with the increased heat, and authorities must start planning the city's tree cover with future conditions in mind.