Research increasingly suggests that moderate to vigorous physical activity (MVPA) is essential to children's health. However, little is known about the extent to which and when different urban environments influence the extent to which children engage in MVPA. To this end, this study explores the relationship between children's MVPA and urban land use and land cover (LULC) for several temporal subdivisions of children's weekly routines (before school, after school and weekends). In particular, the location and corresponding level of physical activity of 4th grade students (n = 134) was recorded using paired global positioning system (GPS) receivers and accelerometers over 33 days for each student. GPS locations were temporally related to accelerometry records and then geographically related to 13 categories of LULC. Mixed linear models were fitted to evaluate the extent to which duration spent in each LULC category can explain individuals' time in MVPA before school, after school, and during the weekends. Geographic cluster analysis was also applied to assess whether any significant spatial relationships between observations of MVPA may exist. Duration of exposure to vegetated parks/open spaces, built residential, and built institutional LULC was found to significantly increase children's time spent in MVPA. Further, most observations of MVPA were found to exhibit significant geographic clustering and were predominately associated with built residential areas (particularly those near schools), indicating the importance of neighborhoods and areas in close proximity to children's households on their level of physical activity. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.