ABSTRACT Building situational awareness has become a central logic among contemporary security apparatuses for abating no-warning urban terrorism. Situational awareness, we contend, casts the sensory, perceptual and affective capacities of human bodies to decipher their immediate surroundings and attune to the non-representational and more-than-known of an enfolding situation, as essential to its execution. What modalities of sense-making and attunement, then, does this burgeoning security rationality demand? And what sensibilities, affectivities and subjectivities are (re)produced and legitimated across urban life? In this paper, we unpack these questions by examining the ways affective and atmospheric attunement(s) are infused within orthodox and emergent security approaches for developing and honing situational awareness. We argue that affective atmospheres in particular furnish the theoretical architecture for attending to the spatio-affective-material registers through which imminence becomes palpable. Empirically, by analysing the Public Inquiry following the 2017 Manchester Arena attack, we elucidate where the Inquiry advanced discussions on (the limits of) situational awareness and its sensorial, affective and atmospheric dimensions, thereby extending situational awareness into an atmospheric agenda within urban geopolitics. Finally, we reflect on how the impending UK Protect Duty might reconfigure the legal landscape of situational awareness, city resilience, and the affective economies of (in)attention.