Climate change adaptation measures like unsealings can reduce urban heat stress. As grass grid pavers have never been parameterized for microclimate model simulations with ENVI-met, a new parameterization was developed based on field measurements. To analyse the cooling potential, scenario analyses were performed for a densely developed area in Cologne. Statistically significant average cooling effects of up to −11.1 K were found for surface temperature and up to −2.9 K for 1 m air temperature.

Sensitivity analyses for wind direction effects upon an ENVI-met microclimate model were performed for a heterogeneous urban study area. Significant temperature differences were found when forcing the model with constant N/E/S/W wind direction data. Best model performance was observed using measured wind direction forcing data. The results demonstrate that cooling effects of park areas are largely directional which is important for urban planning and design of climate change adaptation measures.

Cities are particularly affected by climate change. Adaptation strategies require data, models and scenario analyses. This paper characterizes the urban microclimate of a 16 ha study area in Cologne based on a network of 33 calibrated and validated sensors. Using statistical analyses, tests and pairwise comparisons, significant microclimatic differences were identified between a park, courtyard, avenue and narrow street. The data will be used in future to validate an ENVI-met microclimate model.