Hypereutrophic lake sensor data during summer algae blooms in Iowa, USA, 2014 - 2018

High frequency measurements of temperature, dissolved oxygen saturation, pH, chlorophyll a and phycocyanin concentration were measured using a multiparameter sonde in the surface waters of four lakes during the ice-free season to monitor for harmful algal blooms. The lakes are located in the state of Iowa, USA. Green Valley Lake as monitored in 2014 and 2015, Blackhawk Lake was monitored in 2015, and Swan Lake and South Twin Lake were monitored in 2018. The high frequency data were aggregated to a daily average value for each parameter in each lake. These data were used to test for statistical early warning indicators of harmful algal blooms.