Extreme heat and drought conditions are affecting water availability in many regions worldwide, leading to negative impacts on human societies, agriculture, and ecosystems. However, current research lacks comprehensive spatiotemporal analysis examining the interplay between multiple hydrological factors and heatwave events (HE), especially in the context of climate change. This research broadly pertains to understanding the dynamics of hydrological factors and their potential responses to HE across the contiguous United States for the period from 2003 to 2022. We analyzed the annual patterns and trends of selected hydrological factors, including surface runoff, evapotranspiration (ET), precipitation, groundwater storage (GWS), root zone soil moisture (RZSM), and total water storage (TWS). Furthermore, we evaluated the average change in hydrological factors before and after HE and performed a geospatial analysis of rainfall and HE. A correlation analysis was also conducted among rainfall, maximum temperature, and heatwave duration during HE. The results highlight distinct regional variations in hydrological factors and statistically significant changes in some of these factors across different regions over the study period. Notably, GWS, TWS, and RZSM generally decreased following HE, while surface runoff and precipitation increased. The analysis also revealed complex relationships between rainfall and HE, showing a higher probability of rainfall at the end of HE. Additionally, we found that the probability of rainfall following HE was significantly higher than after non-HE. These findings bear substantial implications for the prediction and management of water resources in regions affected by heatwaves. Ultimately, this research not only enhances our understanding of the hydrological responses to HE but also provides a robust foundation for further investigations into the impact of climate change on water resources.