The goal of this geometry project is to use Voronoi diagrams, a powerful modeling tool across disciplines, and the integration of technology to analyze spring rainfall from rain gauge data over a region. In their investigation, students use familiar equipment from their mathematical toolbox: triangles and other polygons, circumcenters and circumcircles, area, coordinates, data visualization, weighted averages, probability, and calculator applications. Because Voronoi diagrams become more difficult to construct by hand as points are added to the basic diagram, user-friendly, public-domain software is introduced to help students manage the rainfall data to plot points, partition the plane with convex polygons, and calculate areas. Integrating this modeling unit with technology provides a rich mathematical experience for students. An experience with Voronoi diagrams can help satisfy students' curiosity about what mathematicians do and how their work aids other disciplines while providing a rich mathematical experience. (Contains 9 figures, 1 table, and 9 online resources.)