Can't upvote this enough. In Austin, with us on track to break the record of 100+ degree consecutive days, there is a huge difference between walking along nice, shaded areas and barren sidewalks. The trees don't even need to be that "mature" - I've seen new developments plant grown trees that only take a couple years to really expand.

Like the blog post and other commenters mentioned, it's not just trees alone but especially in hotter climates it can make all the difference.