The Arctic Ocean is undergoing rapid changes due to global warming and the reduction in sea ice, affecting its carbon cycle. Sparse observations of surface partial pressure of CO2 (pCO2) limit our understanding of these changes. Here, we use continuous fields of surface pCO2 derived from a gap-filling technique to assess regional and temporal variations in pCO2 at high latitudes. We find an increase in the annual mean pCO2 throughout most of the Arctic. However, the rate of change since 2005 varies strongly between regions. By performing a spatio-temporal decomposition via empirical orthogonal function (EOF) analysis, we suggest two primary drivers of seasonal variability, namely solar irradiance correlating negatively with pCO2 in the sub-Arctic and seasonal variations in the sea-ice cover correlating with the pCO2 in the high Arctic. Unraveling these dynamics is a crucial step toward better understanding the processes governing the Arctic’s carbon cycle in the future.