A review of hydrological conditions throughout the period of the LOIS monitoring programme—considered within the context of the recent UK climatic volatility

Abstract Large spatial and temporal variations in rainfall, with a tendency towards enhanced seasonal contrasts, have combined with unprecedented temperatures to produce wide departures from the normal runoff patterns throughout the LOIS monitoring program. This paper documents the historically very atypical climatic framework within which the programme has operated, and considers it within the context of both the recent notable hydrological volatility at the national scale and the general climatic variability experienced over the last 25 years. Significant departures from long term average conditions are identified which are broadly consistent with a number of currently favoured climate change scenarios—these suggest that a particular benefit of the LOIS study may be to provide insights into hydrological processes and issues which may be expected to assume a greater importance in a warmer world.