Nowadays, distribution network operators are urged by regulatory bodies to reduce load interruptions to users due to extreme weather events, therefore to improve the resilience of the network: in particular, in Italy they must present an annual plan (called ‘resilience plans’) which describe the measures to improve the resilience of the network. To do this, they need new methodologies and tools to assess network resilience and quantify the benefits of countermeasures. This paper proposes the application of a risk-based framework and tool to assess the impacts of extreme weather events in T&D networks and anticipate critical network situations in the presence of looming weather threats. To do this, forecasting weather events is combined with component vulnerability models in order to predict which components have the highest probability of failure. Based on this set of components, the set of highest-risk contingencies is identified and their impacts on the distribution network in terms of load not supplied are quantified. The main advantage of the applied methodology is its general nature: it is in fact applicable to both distribution and transmission systems, as well as to integrated transmission and distribution (T&D) systems, considering the peculiarities of each type of network, in terms of operation, maintenance and vulnerability of components. In particular, the application refers to a distribution network connected to a portion of the national high voltage transmission system in a mountainous area, with focus on two main threats in the area, namely wet snow and tree falls caused by combined wind and snow. The methodology also quantifies the benefits to the resilience of the system of some countermeasures such as reconductoring, optimal reconfiguration or new maintenance procedures for the buffer zone of the lines. The simulations demonstrate the methodology’s capacity to support T&D operators in an exercise planning context under various looming threats.