Studying human activity in coastal areas is crucial for urban planning, sustainability, and economic development. However, there is limited evidence of ongoing monitoring of human activities in these areas. Thus, a quantitative analysis of the spatio-temporal changes, trends, and variability of Nighttime light (NTL) in the Italian Coastal Zone over the past decade (2014–2023) was conducted to assess human activity dynamics. The findings of our study indicate the following: (1) NTL increases over the years in both extent and intensity along the coastal zone; (2) NTL extent and intensity vary by season, with the coastal zone being brighter in summer; and (3) a highly heterogeneous NTL pattern was found where some locations became hot spots (significant upward trend) or cold spots (significant downward trend) while others remain unchanged. By explaining the intensification of human activity, this study can provide insight into identifying the patterns of economic development and environmental conditions contributing to more effective planning in coastal zones.