Trend analysis of precipitation, temperature and snow water equivalent in Lombardy region, northern Italy

The analysis of precipitation, temperature, and snow water equivalent (SWE) trends offers a scientific approach for understanding the impacts of climate change. This paper presents a comprehensive analysis of climate change indicators in Lombardy, Italy, covering the yearly and monthly trends of precipitation and temperature from 1990 to 2020. Additionally, the yearly and monthly SWE variations. For this purpose, a range of statistical tests have been used including Mann–Kendall, Pettitt’s change point detection and Sen’s slope estimator. Precipitation trend shows a slight annual increase of around 5.42 mm per year. This trend is not statistically significant with a Mann–Kendall p value of 0.1448 and no changing point has been detected. Moreover, seasonal precipitation patterns show minor variations, with Kendall’s Tau values ranging from − 0.0431 to 0.1761. However, none of these trends are statistically significant, as reflected in Mann–Kendall p values ranging from 0.1679 to 0.7339. Conversely, Lombardy is experiencing a significant annual temperature increase of 0.0436 °C. Notably, in Autumn, temperatures rise at a rate of 0.0565° per year. Summer also shows a significant warming trend, with temperatures increasing by 0.0421° per year. In Winter and Spring, there are milder, non-significant temperature trends, with Kendall’s Tau values around 0.17. SWE trend shows minor annual variations (5–10%) and monthly shifts. Winter shows a slight decrease (2–3%), implying delayed snow accumulation, while Spring indicates minor change (1–2%) suggesting earlier snowmelt. This study emphasizes temperature's strong impact on SWE and stresses the importance of climate monitoring and collaboration for understanding changing climate patterns.