Northwest Arkansas is rapidly urbanizing, with 30 people moving to the area every day. Rapid urbanization is often accompanied by elevated nutrients, putting downstream habitats at risk of eutrophication and harmful algal blooms. Despite these critical consequences, most urban research compares urban systems to pristine environments or focuses solely on nutrient concentrations. This limits our understanding of how nutrient export varies spatially and temporally within a broader urban area. Here, we quantified nutrient loads at a high spatiotemporal resolution to determine what factors controlled nutrient export across an urban landscape. We collected biweekly nutrient samples (nitrate [N], and soluble reactive phosphorus [P]) and streamflow at 20 urban stream sites across Fayetteville, Arkansas. We also conducted opportunistic storm sampling to understand how storms control nutrient loss from urban systems. We found that both N and P loads had a positive relationship (N: p<0.0001, P: p<0.0001) with subwatershed impervious cover and a negative relationship with subwatershed canopy cover (N: p<0.001, P: p<0.05), regardless of season. In contrast, riparian landscape characteristics were only seasonally important (e.g., canopy cover had a positive relationship with SRP loads in the spring). During storms, relationships between load and landscape characteristics were highly variable and storm dependent. We also found that each of our watersheds were highly spatial unstable, likely due to landscape heterogeneity in the area. Our research suggests that urban water quality must be managed at the watershed scale to account for both the spatial heterogeneity of urban areas and seasonal variation in nutrient dynamics to effectively protect water quality.