An evaluation of the competitiveness of the Northern Sea Route (NSR) for container shipping services, considering ice thickness changes during the year, is presented in the present work. The variation in ice thickness has three implications. Firstly, it entails a probability of blockage in ice and reduces the number of days in which a round-trip liner service can be completed. Secondly, ice thickness impacts schedule integrity. Thirdly, it impacts costs (icebreaker fees and fuel consumption), transit time, and the amount of CO2 emitted per TEU. Accounting for these elements in a model and then in a business case, this study concludes that NSR liner services are only competitive, compared with the Suez Canal Route or the Trans-Siberian Railway Connection, for a limited period of 1.5 months per year.