Urban heat Islands (UHIs) may constitute a hazard for urban populations, particularly under extreme events such as heatwaves. Lisbon is a medium-size city regularly affected by heatwaves with maximum temperatures >35 °C and is expected to grow and densify during this century.

This study evaluates the UHI in the Municipality of Lisbon (ML) for the heatwave with the highest maximum average temperature identified in long-term (2081–2100) RCP8.5 scenario climate simulations, relative to present conditions, represented by a typical heatwave identified in historical (1986–2005) period climate simulations. The expected future consolidation of the city (up to 2100) is considered, as well as the anthropogenic heat and irrigation effects. Simulations are performed with the Weather Research and Forecasting model (WRF) coupled with the Single-layer Urban Canopy Model (SLUCM). The results reveal that urban irrigation effects compensate anthropogenic heat due to increased latent heat release. The expected city consolidation up to 2100 produces the largest increase in the UHI intensity (UHII) during nighttime due to the introduction of urban land use land cover (LULC) with reduced green fraction. No evidence of synergistic interactions between UHI and heatwave intensities were found, with the UHII mostly depending on wind direction and intensity.

城市热岛 (UHI) 可能对城市人口构成危害，尤其是在热浪等极端事件下。里斯本是一个中等规模的城市，经常受到最高气温超过 35 °C 的热浪影响，预计在本世纪将增长和密集。

本研究评估里斯本市 (ML) 的 UHI 热浪，该热浪在长期（2081-2100 年）RCP8.5 情景气候模拟中确定的最高平均温度相对于当前条件，由确定的典型热浪表示在历史（1986-2005）时期的气候模拟中。考虑了城市的预期未来整合（至 2100 年），以及人为热量和灌溉效应。使用天气研究和预报模型 (WRF) 以及单层城市冠层模型 (SLUCM) 进行模拟。结果表明，由于潜热释放增加，城市灌溉效应补偿了人为热量。由于引入了减少绿化率的城市土地利用土地覆盖 (LULC)，预计到 2100 年的城市整合会在夜间产生最大的 UHI 强度 (UHII) 增加。没有发现 UHI 和热浪强度之间协同相互作用的证据，UHII 主要取决于风向和强度。