Summary:

This work analyses the variability of water consumption in Toruń over the years 2014-2017. The difference between the largest annual water consumption (2016) and the smallest (2014) was 13.2%. Higher consumption values typically occurred in the warm half-year, except in 2015. The lowest values occurred in the winter months (February), and the highest in the summer months (from June to August). The largest dayto-day variations in water abstraction were recorded at Easter and Christmas. There were differences between the average water consumption on particular days of the week, with the largest differences being between Saturdays (the highest value) and Sundays (the lowest value). Average unit water consumption was in the range of 58.2 to 67.3 dm3∙M-1∙d-1. On the basis of multiple regression analysis, a set of the factors with the greatest impact on the daily variability of water consumption in the city (in the warm half-year) was indicated. These factors include:
evaporation, day of the week, humidity and maximum temperature.