Water temperature data is collected for different reasons and in different locations. Time series of surface water temperatures can provide indicators of climate change and associated ecological responses. An archive was created in 2007 as part of a research project, and is a unique collation of Natural Resource Wales and The Environment Agencies water temperature data from more than 30,000 sites across England & Wales. The archive contains water temperature data (up to 2007) and site metadata. The archive contains water temperature data (up to 2007) and site metadata. Most sites have records starting from the 1980s.