Proliferating streetlights generated complex emotional responses in modern cities. Drawing on recent scholarship in the history of the emotions, this article argues that examining the feelings of pride and prestige associated with technological innovation, but also of anger and fear when light was lacking or unpleasant, reveals the intimate nature of urban dwellers’ relationship to their environment. Street lighting is often studied as part the networks of infrastructure that gave cities their contemporary form, or as elements of the commercial expansion that made them centers of consumerism. At the intersection of these trends stood the emotional experiences of those seeking to lay claim to the urban night. If the cultural significance of emotions varies according to historical circumstances, comparing the tensions, politics, and atmospheres of streetlights in distant places like Montreal and Brussels suggests that the rapidly changing urban environment of the period produced its own distinct emotional regime.