Rainfall statistics

SAAR – Standard Period Average Annual Rainfall

SAAR is a description of the average annual rainfall across a catchment over a given 30-year period (1991-2020, 1961-1990, 1941-1970). These statistics are derived from the 30-year average 1km gridded maps based on data from the Met Office, rather than a catchment rainfall series. 

SAAR₉₁₂₀ is directly based on the Met Office HadUK gridded rainfall products. SAAR₆₁₉₀ and SAAR₄₁₇₀ are based on similar Met Office grids, but were subject to slightly different methods for temporal and spatial averaging and infilling.

Spatial representations of the distribution of average rainfall across catchments are also based on these gridded datasets for their respective standard periods.