You beat me to it
@trtcttc. 100% the climate down in the lower parts of the intercity are different than outer areas of the city.
My best guesstimation on the heat island effect for the core is a couple of things, one is the amount of concrete and cement, the other is elevation.
A few years back I used to do deliveries, and I had a temperature gauge in the vehicle showing the outside temperature, always without failure if I went from downtown up to say Edgemont, Hawkwood, Coach Hill or one of those neighbourhoods that sit at higher elevations the temperature would drop as I got higher in elevation, and the temperature would rise as I went back downtown again.
In the evenings during summer, spring and fall the temperature change was very consistent and almost always was about 5° difference between downtown and those higher elevation neighbourhoods. The difference was even higher around 9PM to midnight, where downtown and the Beltline could be as much as 10° warmer than Edgemont where I lived at the time. During the winter didn’t vary as much.
During summer fall and spring if I went from downtown out to a neighbourhood at the edge of the city in the south, such as Canyon meadows or Bonavista the temperature was usually about degrees 2-3 degrees cooler, and not as pronounced as it was for the northwest.
I've noticed 100% is downtown and Beltline retains its heat far longer after sunset than other neighbourhoods. This goes back to the amount of concrete and asphalt I would imagine.
Anyhow, this isn’t to say climate change isn’t having an effect, because I think it’s having an effect, but that the heat island is also very real.