But a new study by a Concordia researcher takes a closer look at the phenomenon and what can be done to mitigate it.
"We found that to get the most cooling, you have to have about 40 per cent canopy cover, and this was strongest around the scale of a city block," she says.
"So if your neighbourhood has less than 40 per cent canopy cover, you'll get a little bit of cooling, but not very much.
Once you tip over that threshold, you really see large increases in how much you can cool areas off.".
Her research shows that during nighttime there is a much smaller difference in temperature between areas with significant canopy cover and those without.
"Once you have a certain critical mass of canopy, then each tree becomes more important when it comes to cooling temperatures.
Read the cited paper: "Scale-dependent interactions between tree canopy cover and impervious surfaces reduce daytime urban heat during summer. »