This is a long-term monitoring dataset of surface temperature, surface oxygen, water clarity, water chemistry and phytoplankton chlorophyll a from weekly or fortnightly sampling at the North Basin of Windermere in Cumbria, England. Monitoring began in 1945 for some variables. The data comprise surface temperature, surface oxygen saturation, Secchi depth, alkalinity, ammonium, nitrate, soluble reactive phosphate, total phosphorus, dissolved reactive silicon and phytoplankton chlorophyll a. Water samples are based on a sample integrated from 0 to 5 m (1945-1962), 0 to 10 m (1962-1964) and 0 to 7 m (1964 onwards). Measurements are made from a boat at a marked location at the deepest part of the lake. All data are from February 1945 until the end of 2013 and were initially collected by the Freshwater Biological Association but have been collected by the Centre for Ecology & Hydrology (CEH) and its predecessor Institute of Freshwater Ecology since 1989. Full details about this dataset can be found at https://doi.org/10.5285/f385b60a-2a6b-432e-aadd-a9690415a0ca
