This project analyzed the effectiveness of a city-wide wireless weather sensor network, the Taipei Weather Science Learning Network (TWIN), in facilitating elementary and junior high students' study of weather science. The network, composed of sixty school-based weather sensor nodes and a centralized weather data archive server, provides students with current weather data at specific locations in the city. In 2006-2008, annual weather science tournaments were held to encourage students to use this resource, and up to now 171 registered teams, including 447 grade 4-9 students and 220 teachers, have participated in competitions. This study of the tournament data makes clear the over-all efficacy and usability of the network. An analysis of the students' weather science ability demonstrated that they could perform well in the questioning phase, the planning phase and the analyzing phase but not as well in the interpreting phase of their specific weather-science inquires. (Contains 4 tables and 5 figures.)