###### Abstract  
This study presents the potential impacts of climate change in 49 Polish cities by analyzing seven climate indicators. The analysis was carried out for the following three horizons: the current climate conditions (an average period spanning 2006 to 2015), near-future conditions (an average period spanning 2026 to 2035), and future conditions (an average period spanning 2046 to 2055). Climate indices were computed with bias-corrected EURO-CORDEX model ensembles from two Representative Concentration Pathway scenarios, RCP4.5 and RCP8.5. The systematic error was reduced using the quantile mapping method with a non-parametric approach of robust empirical quantiles (RQUANT). Data were used as references in the period of current climate conditions, and those required for bias correction consisted of historical ground-based observations provided by the Institute of Meteorology and Water Management. The analysis encompassed various key climate indices, including the annual average temperature, the count of hot days, cold days, and frost days, the cumulative annual precipitation, the frequency of days with precipitation, and instances of extreme precipitation (defined as the days with precipitation exceeding 10 mm/day). These findings reveal a noteworthy rise in the average annual temperature of approximately 1 \({}^{\circ}\)C and an uptick in the number of hot days by 3.7 days. Conversely, a decline in the number of cold days by approximately 19 days and frost days by 8 days was observed. Additionally, there was an augmentation in the annual precipitation sum, reaching up to 80 mm in RCP 8.5, accompanied by an increase in the number of days with precipitation (up by 3.3 days) and days with extreme precipitation (up by 2 days). EURO-CORDEX; RCP scenarios; climate indices; climate projections; climate downscaling 2020 2  
change depends on socioeconomic policy development and the resulting greenhouse gas emissions [7; 8]. An increase in global surface temperature indicates a rise in the length and frequency of heat waves [9; 10; 11]. It directly impacts the hydrological cycle, causing increased floods and droughts in Europe [12; 13; 14; 15]. Research conducted by [16] indicates an increase in the mean annual number of summer days (Tmax \(>\) 25 \({}^{\circ}\)C) in Krakow, in scenario RCP8.5, by 192% (in the period 2071-2100 related to 1971-2000). Another research performed by [17] demonstrates a significant increase, in scenario RCP8.5, of the monthly mean temperature in the hottest month in cities by 4 to 7 \({}^{\circ}\)C (by 2100), suggesting that this usually exceeds the threshold for heat deaths.This hazardous phenomenon cannot be neglected, especially the excessive mortality observed and analyzed in, e.g., [18; 19; 20; 21]. Therefore, research on the impact of global climate change on urban areas is vital to city inhabitants. Moreover, since the future of socioeconomic development is unknown (it can only be assumed with predictions), information about the future climate conditions needed for adaptation plans must be acquired from available emission scenarios. The motivation for the work is related to the needs of the Polish Ministry of Climate and Environment (former Ministry of Environment). A dedicated, innovative project, MPA44 (\"Developing climate change adaptation plans for cities with more than 100,000 inhabitants\", [http://44 mpa.pl/](http://44 mpa.pl/) (access on 12 December 2023), was conducted to develop adaptation plans for climate change in cities with populations exceeding 100,000. The main objective was to assess the climate change sensitivity of the 44 largest Polish cities and plan adaptive actions adequate to the identified threats. Preparing urban adaptation plans in these 44 cities contributed to protecting approximately 30% of Poland's population from the effects of climate change. Also, implementing this project triggered similar actions at the local level in smaller cities and municipalities.