Against the backdrop of global warming, assessing the effects of climate change on hydrological processes is crucial for local water resource management. Variations in temperature, precipitation, and runoff at four different timescales in the Fuhe River Basin were evaluated based on observational data collected from 1960 to 2020 using the Mann–Kendall test. The findings indicated significant increases in average temperatures for the annual, flood season, and non-flood season periods, rising by 0.0197, 0.0145, and 0.0278 °C every annum, respectively (p < 0.01). Precipitation exhibited non-significant upward trends at all timescales (p > 0.1). The trend in flood season runoff was also non-significantly upward, whereas annual runoff and non-flood season runoff displayed non-significant downward trends (p > 0.1). Flood season temperature decreased with increasing altitude, exhibiting a significant Pearson correlation coefficient of −0.744 at the 0.01 level. Conversely, annual, flood, and non-flood season precipitation significantly increased with increasing altitude, with Pearson correlation coefficients of 0.678 at the 0.01 level, 0.695 at the 0.01 level, and 0.558 at the 0.05 significance level, respectively. Precipitation and runoff exhibited similar trends throughout the year, increasing initially and then decreasing over time, reaching maximum values in June. Climate change is likely responsible for the hydrological alterations in the study basin. The findings of the study could provide references for water resource management decisions in the Fuhe River Basin.