rotorua_chl_fields_2015-2020.nc is a time-series of 283 Chl fields of the Rotorua lakes (New Zealand) derived from Sentinel-2 MSI images with a regionalization of the C2RCC algorithm in a 60 m resolution. It also includes C2RCC and Idepix masks as well as a shoreline-and-shallow-water-buffer for flexible quality flagging. rotorua_chl_spatial_variability.tif is a GeoTIFF that illustrates the representativeness of each grid cell for the Chl distribution in each lake and thus indicates recurring spatial patterns. The file contains three bands that contain the relative frequency (in %) the Chl concentration in a grid cell was within 5 % to either side of the lower quartile (25 % percentile, first band), the median (second band) and the upper quartile (75 % percentile, third band) of the lakes Chl distribution. rotorua_insitu_chl_2015-2019.csv contains 831 in-situ Chl measurements of the monthly Bay of Plenty water quality monitoring programme and samplings by Moritz Lehmann from 12 of the Rotorua lakes collected between 2015 and 2019. shoreline_shallow_water_buffer.zip contains a shapefile with polygons of the “optically deep” areas of all Rotorua lakes to remove areas contaminated by bottom reflectance in remote sensing products. Each polygon has a 120 m shoreline buffer to avoid mixed land-water pixels and reduce adjacency effects. It further excludes lake areas shallower than the 95 %-quantile of all Secchi depth measurements of the Bay of Plenty water quality monitoring programme.