FUV fluxes experienced by discs in six star-forming regions in Orion. The different colours correspond to the different methods for the calculation of the FUV flux, as introduced in Sect. 4. The dashed lines show median FUV flux values for each region and for the calculation method. The x-axis contains the distance from the most massive star in the region. In NGC 2024, the local density distribution method cannot be applied (and therefore, no orange points lie in that panel), as an accurate density profile of the region cannot be currently retrieved.