The rainfall data recorded on the Oir river watershed are made on two sectors: at Cerisel mill and on the brook of La Roche (tributary of Oir river) for the Environmental Research Observatory (ERO) on Diadromous Fish in Coastal Rivers (DiaPFC). The DiaPFC ERO is a research infrastructure focused on the study of the evolution of diadromous fish populations under the influence of environmental and human-induced changes (mainly agriculture and climate). The Oir is a tributary of the Sélune: a coastal river that flows into the Mont Saint Michel bay. This river extends from West to East on 13.5 km and drains a catchment area of 85.4 km². The average flow is 1.09 m3/s. Agriculture and more particularly cattle breeding is the main human activity developed on this watershed. The Oir is colonized by several species of migratory fish: atlantic salmon, european eel, sea and river lampreys, sea trout... For the data recorded at Cerisel mill: The recording of the rainfall is carried out at the following geographical position: latitude: 48.627724; longitude: -1.273841 with an automatic rain gauge with troughs whose resolution is of 0.2 mm by tilting. The data are recorded since 07/20/2008. For the data recorded at the level of the brook of the Rock: The recording of the rainfall is carried out at the following geographical position: latitude: 48.647629°; longitude: -1.170500° with an automatic rain gauge with troughs whose resolution is of 0.2 mm by tilting. The data are recorded since 01/27/2010.