Global warming is a significant environmental problem that currently affects a wide variety

of organisms. The Urban Heat Island (UHI) phenomenon, in which urban areas have hotter

temperatures than nearby rural or suburban areas, is caused by urbanization. However, global

warming amplifies the effects of UHI, which in turn may intensify global warming trends.

Weather patterns, species behaviors and habitats, water resources, and air quality are all

significantly impacted by this temperature increase. As a result, many nations experience

negative effects on their social, economic, health, and environmental conditions. This article

focuses on Colombo, a rapidly developing city in Sri Lanka, as a case study to investigate the

causes, impacts, and mitigation methods of urban heat islands. The study primarily utilizes

secondary data collection methods, drawing information from research articles, journals,

publications, annual reports, relevant books, and credible online sources. The secondary

data were analyzed qualitatively and presented descriptively. The research findings reveal

the pronounced urban heat island effects in Colombo. the city’s Urban Heat Islands (UHIs)

have a number of negative effects, such as elevated emissions of air pollutants, weakened

human health, changed weather patterns, and worsened water quality. The loss of natural

landscapes, the thermal properties of urban materials like concrete and asphalt, heat

retaining urban geometry, and increased human activity are some of the contributing factors

to these effects. Greenhouse gas emissions and population growth contribute to UHI as

well as to climate change. Furthermore, topography may influence the distribution of local

temperature distribution. The study suggests several measures to lessen these issues in

Colombo, such as creating sustainable urban infrastructure, increasing the number of trees

and other vegetation, installing green roofs or reflective cool roofs, putting cool pavements

in place, adapting smart growth principles, and encouraging effective transportation systems.