Wave is an effective physical oceanographic parameter essential for human maritime activities, such as ships' navigation, coastal engineering and sediment transportation. Hourly wave data records were acquired from four buoys, deployed in different locations: Alexandria Western Harbor, Alexandria Eastern Harbor, Port Said Harbor, and Rashid site along the southeastern coast of Egypt, utilized for validating waves 'hourly data, obtained from the European Centre for Medium-Range Weather Forecasting Reanalysis. Results revealed that the mean direction of waves using wind rose analysis is north-west-north for all offshore deep-water buoys in both datasets. In contrast, the results from onshore shallow-water buoys in AWH were in a different direction, with a weak correlation value (0.04). Furthermore, the differences in mean significant wave height of offshore buoys ranged from −0.17- 0.14m, respectively, and correlation values were 0.88, 0.96 and 0.96. Meanwhile, the differences in the same data SWH from onshore buoys fluctuated between 2.9 and 2.96m, with a correlation value of 0.73. In addition, the root-mean-square error in SWH ranges between 0.001 and 0.126m. Moreover, the standard deviation does not exceed 0.89m and is even as low as 0.16m at all far sites. While, in the near coast locations, it reaches up to 1.53m. Accordingly, the mean zero-crossing period correlation between the two datasets was 0.14, 0.91, and 0.89, while in the near coast buoy, it was 0.069. Meanwhile, the bias in the mean zero-crossing period between both datasets (ERA-5 and buoy) showed a difference in the mean ranges from 0.08 s to 1.6 s. Finally, from the analysis of the three main wave parameters, the validity of ERA5 wave data was confirmed, except for the shallow nearshore areas as well as the low-depth sensor due to its low accuracy.