Using a new low-temperature apparatus for single crystal X-ray diffraction data collection, the structure of SrFe 12O 19 M-type hexagonal ferrite was refined at 4.6, 8, 22, 40, 70, 100, 200, 240 and 295 K. Previous Mössbauer spectroscopy results had shown that, at room temperature, the Fe2 iron in the bipyramidal site is dynamically disordered between two close sites. We show that, below 55 K, this disorder probably becomes statistic. Using the space group P 1 for Fe2 and its three nearest neighbour oxygens, we found that, at room temperature, these three oxygens are probably also jumping between two close sites, but perpendicularly to the Fe2 jumping direction. Below 55 K, as Fe2, these three oxygens are also statistically disordered between their two possible sites. Therefore, we propose a new representation of the bipyramidal site.