The video of the workshop can be found here.
Maps showing the perceived temperature during a hot day are useful to point out cool spots and areas with high heat stress that could be designed more heat-resilient. Maps with nighttime temperatures are especially relevant to indicate problems related to indoor climate, health and labor productivity. However, there are quite a few uncertainties in the design and the use of the current map of the number of warm nights that exists for the Netherlands.
First of all, it can be argued if the number of warm nights is the best indicator to understand the problems related to nighttime heat. And if so, could this indicator also be used as a basis for guidelines to reduce problems related to nighttime heat or for formulating heat-resilient ambitions? Or should other climate indicators or maps be used instead? Knowledge about nighttime temperatures and its spatial variation in cities is for instance important to understand if specific urban areas are more vulnerable with respect to nighttime heat and increased indoor temperatures.
Information on nighttime temperatures is also needed to assess the options for natural window ventilation to reduce indoor temperatures, and to understand to what extent the urban heat island effect or the percentage of greenery influences the cooling potential of homes or other buildings in a city. It is likely that the number of warm nights is not the appropriate indicator to examine this.
The desired outcome of this workshop is a description of a map or data on nighttime temperatures to include in the climate impact atlas. Besides, this workshop may also lead to a joint research proposal for making a new nighttime temperature map.