The Normalised Difference Vegetation Index (NDVI) dataset details surface reflectance measured as NDVI. NDVI provides a proxy for the amount and/or the relative 'greenness' of vegetation. Data collection was carried out at six intertidal sites in the winter and summer of 2013. Three of the sites were in Morecambe Bay, North West England and three of the sites were in Essex, South East England, each of these sites consisted of a saltmarsh area and adjacent mudflat area, twenty two sampling quadrats were placed on each area. A single NDVI observation was taken at each quadrat. Spectral reflectance was measured using a portable spectrometer. This data was collected as part of Coastal Biodiversity and Ecosystem Service Sustainability (CBESS): NE/J015644/1. The project was funded with support from the Biodiversity and Ecosystem Service Sustainability (BESS) programme. BESS is a six-year programme (2011-2017) funded by the UK Natural Environment Research Council (NERC) and the Biotechnology and Biological Sciences Research Council (BBSRC) as part of the UK's Living with Environmental Change (LWEC) programme.