Updated precipitation series for the UK derived from Met Office gridded data

This paper introduces new, homogenized UK national and regional rainfall series derived from 5-km gridded daily and monthly precipitation data. These new series have the advantage that they are based on readings from a dense network of rain gauges rather than a maximum of seven per region. Series developed by alternative statistical methods are analysed and compared. Error estimates are derived for the series, based on linear regressive residuals. Using individual regressions for each calendar month, the monthly series are extended back to 1766 for monthly precipitation in England and Wales (EW), to 1873 for monthly values for each of the five EW sub-regions, and to 1931 for daily values in all regions. A follow-up paper will provide analysis of how mean precipitation totals and extremes have changed over the respective periods.