This dataset contains time series observations of surface-atmosphere exchanges of sensible heat (H) and latent heat (LE) and momentum (τ) measured at UKCEH eddy covariance flux observation sites during summer 2019. The dataset includes ancillary weather and soil physics observations made at each site. Eddy covariance (EC) and micrometeorological observations were collected using open-path eddy covariance systems. Flux, meteorological and soil physics observations were collected and processed using harmonised protocols across all sites. This work was supported by the Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme delivering National Capability. Full details about this dataset can be found at https://doi.org/10.5285/0254620f-9cf1-4d5b-af3f-bd8a6af95e96