Heat islands in Santiago de Chile: Qualitative and quantitative analysis using Lamb weather types

Studying the temporal and spatial evolution as well as the intensity of UHI (urban heat island) is key to understanding the effects of climate change. This is the first study in the City of Santiago, Chile, that combines the effects of UHI and its interaction with synoptic patterns. The present article considers UHI over the city of Santiago with a spatial resolution of 0.05° over a period of 61 years, from 1960 to 2021. Maximum and minimum air temperatures were used. A UHI was not observed during the day, as the temperatures mostly cover a large part of the rural area adjacent to the city and do not seem to be influenced by the urban area. At night, it was possible to observe a UHI located in the central, northern area of the urban area. It was found that the different Lamb types and the different seasons influenced the UHI. The northwest area of the city showed the greatest temperature contrasts. Finally, positive trends were found for T_max within the city of up to 0.21 °C/10 years, and for T_min of up to 0.19 °C/10 years, thus allowing climate change effects to be quantified.