In the tourism literature, seasonality issues are widely existing in almost every destination and well documented particularly in some case located where it is peripheral, and cold-weather. Hotels and entrepreneurs attracted most attention due to the negative effects of seasonality on their business. This is problematic actually the non-profit making actors play a significant role in supplying touristic resources and marketing a destination. Therefore, museums’ responses to seasonality make sense. This thesis, therefore, applying an institutional analysis, examines seasonal patterns of the museums and their knowledge of tourism seasonality, investigates positive and negative effects of seasonality on the museums, and finds out how they tackle seasonality. The aim is to improve understanding and increase knowledge of tourism seasonality and complement the previous research on tourism seasonality with museum perspective. Both descriptive statistics and interviews are applied to serve the aim. The analysis of statistics supplies a statistical seasonal pattern of the study location while four informant interviews were conducted with respondents from tourism organizations and museums. The results show that the seasonal pattern of museums is highly relevant to the seasonal pattern in Umeå. For the museums the negative effects varied from one to another but outweighed the positive ones for all of them. Three strategies are addressed in the way that these museums tackled seasonality. Institutional performance is evaluated in the discussion chapter followed by suggestions for future work.