It is evident that convex spaces create heat pockets; so what if we augmented our architecture for reflection or at least in a similar manner as anechoic chambers and made it difficult for heat to bounce off?
I understand that this will likely cause higher floors to accumulate more heat, but the surface area getting heated will be larger and thus not concentrated on the road / street level. This is likely a problem for American buildings as they usually have thinner walls.
One such way to construct such surfaces would be planting trees vertically which give shade and absorb heat; though this is likely a maintenance problem.
Streets unfortunately have little space for trees unless of course dependence on cars is reduced and public transportation, bikes and walking become the main methods of commuting as in eg Copenhagen where > 65% commute on foot or by bike or public transport to go to work.