Daily records of Marine Heatwaves (MHW) intensities and categories resulting from detection conducted on European Space Agency (ESA) Climate Change Initiative (CCI) Sea Surface Temperature (SST) satellite product, regridded to a 1°x1° regular grid, covering the period 01/01/1982-31/12/2021. The MHW detection has been carried out via Hobday's method (Hobday et al. 2016), with the following parameters: At a pixel-wise level a MHW event is detected when the SST value exceeds: - the 90th percentile threshold over climatology reference for 5 consecutive days at least, where - the climatology reference has been computed as the daily average over the whole period (1982-2021). The mhw field describes the intensity of anomaly [°C] of MHW events detected. The cat field gives information on the category of the events detected (1=moderate, 2=strong, 3=severe, 4=extreme). Definition of categories can be found in Hobday et al. (2018). The production of the dataset has been sustained with the support of the European Space Agency (ESA) "deteCtion and threAts of maRinE Heat waves" project (CAREHeat; grant number: 4000137121/21/I-DT) and of Copernicus Climate Change Service Quality Assessment of ECV Products (C3S_511; grant number: C3S_511_CNR) project. References: Hobday, A. J., Alexander, L. V., Perkins, S. E., Smale, D. A., Straub, S. C., Oliver, E. C., ... & Wernberg, T. (2016). A hierarchical approach to defining marine heatwaves. Progress in Oceanography 141:227–238, https://doi.org/10.1016/j.pocean.2015.12.014. Hobday, A. J., Oliver, E. C., Gupta, A. S., Benthuysen, J. A., Burrows, M. T., Donat, M. G., ... & Smale, D. A. (2018). Categorizing and naming marine heatwaves. Oceanography, 31(2), 162-173, https://doi.org/10.5670/oceanog.2018.205