The Phoenix Metropolitan Area (PMA) is one of the fastest-growing areas in the United States. Like many other large metropolitan areas, a pronounced urban heat island (UHI) exists in the PMA. The PMA UHI strengthened noticeably during the 1970s through the 1990s, a period of very rapid population growth. Research has shown that UHIs have the potential to alter precipitation patterns over and downwind of the urban areas. Several studies of anthropogenic effects on precipitation (AEP) in relation to the PMA, conducted during the past five years, appear to confirm the existence of precipitation enhancement “downwind” of the PMA and, presumably, the UHI. However, many of these studies are flawed, either due to poor data sampling (such as point-gauge observations or low-resolution remote sensing) and/or a lack of understanding of the unique convective precipitation patterns commonly observed in central Arizona as a consequence of the local topography and the steering wind regimes commonly observed during the North American Monsoon. This study will incorporate three separate data sets (a point-based rain gauge network, a spatially modeled data set, and ground-based radar) to determine what, if any, AEP exists due to the UHI over the PMA. Data set information will be compared and contrasted, and the superiority of ground-based radar data over point-based rain gauge data will be highlighted.