Long-distance Wi-Fi technology has shown promise in several network applications that cannot utilize conventional technologies effectively. Although the network performance of Wi-Fi technology is affected by a number of environmental factors, there is a dearth of long-term, continuous, and systematic studies on the correlations between those factors and the technology's performance. In this study, we deployed a long-distance Wi-Fi testbed on our campus and conducted a one-year experiment. Comprehensive data analysis of the measurement results shows that rainfall is the major weather attribute that affects the network performance of long-distance Wi-Fi links. In addition, the performance is highly correlated to human activities in the immediate vicinity. The results also demonstrate it is possible to infer people's daily routines on campus by exploiting the long-term measurement data.