Stockholm is expanding fast in response to increasing housing needs. This paper evaluates the consequences of land-use changes on summer temperatures. Urban development scenarios for 2030 and 2050 were developed together with the municipality. The spatial and temporal variations of the changes in the urban air temperature are simulated at 1 km grid resolution applying a dynamical downscaling technique. The comparison against observations obtained during 5 years at 11 weather stations shows that the high resolution model captures the dynamics of the intra-urban air temperature gradients with good performance skills. Scenario results indicate that the temperature of summer 2014 would increase over the new built-up areas by, on average, 0.29 °C in 2030 and 0.46 °C in 2050, up to a local maximum of 1.35 °C in the latter, as a consequence of urbanization. The number of days with temperature above the 75^th percentile for the summer months increases by up to 10, with locations closer to the sea being less prone to temperature maxima. The spatial coverage of this warming effect is predominantly local, occurring mostly over the transformed/densified area. Better knowledge on how urban temperatures are affected by on-going urbanization is needed also in high latitude cities.

斯德哥尔摩正在因应不断增长的住房需求而迅速扩张。本文评估了土地利用变化对夏季气温的影响。与市政当局一起制定了2030年和2050年的城市发展方案。应用动态降尺度技术，以1 km的网格分辨率模拟了城市气温变化的时空变化。与11个气象站在5年中获得的观测值的比较表明，高分辨率模型以良好的性能技巧捕获了城市内部气温梯度的动态。情景结果表明，2014年夏季的温度将在新建成区平均升高，到2030年为0.29°C，到2050年为0.46°C，后者最高达到1.35°C，城市化的结果。温度高于75的天数夏季月份的百分位数增加多达10^个百分点，并且靠近海域的位置不太容易达到最高温度。这种变暖作用的空间覆盖主要是局部的，主要发生在转变/致密化的区域。在高纬度城市，也需要更好地了解持续的城市化如何影响城市温度。