We analyse the average annual and seasonal air temperature conditions in the ‘local climate zones’ (LCZs) of Szeged, Hungary. The basis of our analysis is a 1‐year dataset from 2014 to 2015 for a 20‐station urban meteorological network. The network and its corresponding LCZ classes put temperature studies in Szeged into a new spatial framework to assess local climate and urban heat island (UHI) conditions. The stations were installed at locally representative sites using a Geographic Information System (GIS) method based on the standard surface parameters of the LCZ classification. The network was purposely designed to monitor thermal differences among LCZ classes in Szeged. We provide detailed site metadata for each of the monitoring stations used in the analysis. Our results show that the densely built‐up LCZ classes have higher annual and monthly mean and minimum air temperatures than structurally open and more vegetated classes, with nocturnal differences of >4 °C observed under calm, clear skies. Among select temperature indices measured in the urban LCZ classes, frost days, cooling degree‐days, and tropical nights differ markedly from the background rural LCZ classes. This difference suggests that local climatologies exist within Szeged, and that these have implications for thermal comfort, urban energy use, and urban agriculture. Finally, the evaluation of heating and cooling rates in Szeged shows an important role for LCZs in UHI analysis.

This study gives a comprehensive picture on the diurnal and seasonal general outdoor human thermal sensation levels in different urban quarters based on long-term (almost 3 years) data series from urban and rural areas of Szeged, Hungary. It is supplemented with a case study dealing with an extreme heat wave period which is more and more frequent in the last decades in the study area. The intra-urban comparison is based on a thermal aspect classification of the surface, namely, the local climate zone (LCZ) system, on an urban meteorological station network and on the utilization of the physiologically equivalent temperature (PET) comfort index with categories calibrated to the local population. The selected stations represent sunlit areas well inside the LCZ areas. The results show that the seasonal and annual average magnitudes of the thermal load exerted by LCZs in the afternoon and evening follow their LCZ numbers. It is perfectly in line with the LCZ concept originally concentrating only on air temperature (T ) differences between the zones. Our results justified the subdivision of urban areas into LCZs and give significant support to the application possibilities of the LCZ concept as a broader term covering different thermal phenomena.

Abstract-This paper presents a case study about the surface temperature characteristics of the different Local Climate Zones (LCZ) in Szeged, Hungary. For the evaluation we apply high resolution surface temperature data acquired by a low-cost small-format digital imaging system, measured in early night hours. The map of Local Climate Zones for the study area is derived by an automatic GIS method for LCZ classification. The results show that the different LCZ classes have different surface temperature characteristics. Among the densely populated LCZ classes the open low-rise has the lowest surface temperature, thus it is can be the most favorable urban built-up type if the aim is the decrease the effect of the urban heat load.

Diurnal variability of spatial pattern of air temperature was studied in five cities in Central Europe: Bratislava (Slovakia), Brno (Czech Republic), Kraków (Poland), Szeged (Hungary) and Vienna (Austria), during one of the heat waves in 2015 (4-14 August), with the application of micro-climate model MUK-LIMO_3. 8th August was chosen to study in detail the urban heat load at 10.0 0, 16.0 0, 22.0 0 and 4.00 CEST. Local Climate Zones concept was used to supply data for the model and for the interpretation of the results obtained. Model outcomes were validated with measurement data from 86 points belonging to the networks which operate in the cities studied. The results obtained show that among urban LCZ, the highest heat load was observed for LCZ 2 and 3 from 16.00 to 4.00, while at 10.00 there is no such clear pattern. Unlike forested areas, open green areas can contribute to the generation of high air temperature: > 35 °C during day time and > 30 °C during night time. Important factors controlling the intra-zonal and inter-zonal variability of air temperature in particular LCZs are the local environmental conditions. During the day time, diversified relief in the area of the city and its vicinities generates higher heat load in the valleys' floors than in areas located above, both in rural and urban areas. The same landforms experience lower heat load during the night time due to air temperature inversions effect.

In this paper the spatial patt ern of Urban Heat Island (UHI) and its dynamical background are analysed. Furthermore, we examined the annual, seasonal and diurnal characteristics of UHI according to the Local Climate Zones (LCZs). The analysis was performed using one year (between June 2014 and May 2015) dataset from the measurement network of Szeged (Hungary). This network consists of 24 stations measuring air temperature and relative humidity. In the installation of the network the representativeness played an important role in order to that the stations represents their LCZs. We examined the thermal reactions during average and ideal conditions using the so-called weather factor. Our results show that the UHI is stronger in the compactly built zones and there are great diff erences between the zones. The greatest values appear in summer, while the diff erence is small in winter. The UHI starts to develop at sunset and exists through approximately 9-10 hours and diff erences are about 2 °C larger in case of ideal days, when the conditions (wind, cloud cover) are appropriate to the strong development of the UHI. The cooling rates show that the fi rst few hours aft er sunset are determinative for the developing of UHI. In addition, the eff ect of UHI on annual mean temperature is also signifi cant.