Climatologies, or long-term averages, of essential climate variables are useful for evaluating models and providing a baseline for studying anomalies. The Surface Ocean CO2 Atlas (SOCAT) has made millions of global underway sea surface measurements of CO2 publicly available, all in a uniform format and presented as fugacity, f(CO2). As f(CO2) is highly sensitive to temperature, the measurements are only valid for the instantaneous sea surface temperature (SST) that is measured concurrently with the in-water CO2 measurement. To create a climatology of f(CO2) data suitable for calculating air-sea CO2 fluxes, it is therefore desirable to calculate f(CO2) valid for a more consistent and averaged SST. This paper presents the OceanFlux Greenhouse Gases methodology for creating such a climatology. We recomputed SOCAT's f(CO2) values for their respective measurement month and year using monthly composite SST data on a 1 degrees x 1 degrees grid from satellite Earth observation and then extrapolated the resulting f(CO2) values to reference year 2010. The data were then spatially interpolated onto a 1 degrees x 1 degrees grid of the global oceans to produce 12 monthly f(CO2) distributions for 2010, including the prediction errors of f(CO2) produced by the spatial interpolation technique. The partial pressure of CO2 (p(CO2)) is also provided for those who prefer to use p(CO2). The CO2 concentration difference between ocean and atmosphere is the thermodynamic driving force of the air-sea CO2 flux, and hence the presented f(CO2) distributions can be used in air-sea gas flux calculations together with climatologies of other climate variables.