As part of a heat island study in the City of Ljubljana, 32 temperature and humidity meters were set up in a network at various locations around the city.

The monitoring, which will start on 20 July 2024, will form the basis for creating a digital platform to provide a real-time view of the temperature dynamics at these locations.

The project involves the establishment of a network of air temperature measurements in a dense spatial network of stationary meters, which will be supported by a network of four higher-order stationary meteorological stations operated by the Faculty of Arts at the University of Ljubljana and will also include data from other stationary stations in the city which are transmitting data in real-time (ARSO, City of Ljubljana).

Once the digital platform is up and running, we will use temperature measurements and other features of the city's topography that affect the »heat image« of individual parts of the city to create a map of the urban heat island, which will be displayed on the digital platform in real-time (up to 45 minutes delay from the time of the measurements).

The results will allow us to perform a thorough analysis of the city's heat island for different times of the day, seasons, weather types and even individual parts of the city. In the preparation, network design, measurement and interpretation phases, the project will incorporate existing research findings on the urban heat island in Ljubljana.

The study will provide the following information:

• Real-time city temperature display and dynamic monitoring on the platform.
• Real-time city heat island display and dynamic monitoring on the platform.
• Advanced representation of the climatology of the urban heat island compared to measurements so far, based on a dense measuring network (the densest ever).
• Creation of own measuring network and database on urban climate.
• Identification of hot spots in the city and their intersection with sites that citizens perceive as hot spots.

Measuring equipment

As part of the project, we have partnered with the public company Javna razsvetljava d.d. to install 32 precision meters that will send real-time data to an online platform. The meters operate through the LoraWAN communication system, which also connects to the open infrastructure already set up in the city. They are all shielded from direct sunlight by white shutters, which will significantly contribute to the accuracy and precision of our measurements. In a public call for tenders, the PILEUS company was selected to conduct the study and awarded a three-year contract valued at 46,000 EUR.