Plant Atlas 2020 is the most comprehensive survey of plants (flowering plants, ferns and charophytes) ever undertaken in Britain and Ireland. It is based on over 30 million records, collected mainly by volunteer recorders of the Botanical Society of Britain and Ireland (BSBI) between 2000 and 2019, as well as previous nationwide surveys undertaken in the 1950s and 1990s. This resource contains the species weekly “apparency” metrics presented within the Plant Atlas book and website, including a breakdown of species apparency by latitude for Britain. Apparency at the scale presented here (2 x 2 km spatially, smoothed over the period 2000–2019) combines aspects of recorder activity and detectability, with the latter being primarily influenced by phenology at this spatio-temporal scale.