I must read some articles before replying. I do not make up replies according to a thing I want to advocate. I try to understand things, not to manipulate them. The figure you mentioned suggests that the heat island can go over the highest buildings but I need to learn more. Especially a distinction between small towns, large cities and metropolis would be important. Figure 3 suggest that for cities sized as Athens in population, the increase in temperature due to urban heat island can reach 8°C in Europe.

Thanks for the info about Nea Filadelfia station. Hence, full urban area.

This is a quick example of urban heat island effect in Milan



(Source: CML - Articoli - Isola di calore urbana e rilevazione dei dati - Prima parte)