The information regarding the spatial dependence of metocean conditions is important in the reliable design of coastal structures and various marine engineering activities. The significant wave height is one of the most important wave parameters for coastal and offshore structural design. Climate change and various climate variabilities are expected to change various metocean parameters at global and regional scales. The current study aims to investigate the spatial dependence in the significant wave height over the selected domain (latitude ranges from 9 to 25°N and longitude range from 40 to 105°E) of the Northern Indian Ocean. Wave time series data during the period 1979–2022 from the global atmospheric reanalysis ERA-5 by the European Centre for Medium-Range Weather Forecasts (ECMWF) is used for this study. The collected wave data have a spatial resolution of 0.5° longitude × 0.5° latitude and a temporal resolution of 6 h. From the collected wave data, the seasonal (DJF–MAM–JJA–SON) maximum and annual maximum data series of significant wave height are extracted for the past 44 years (1979–2022). The spatial dependence assessment is carried out for the four seasons (DJF–MAM–JJA–SON) and the annual data. Three correlation methods, namely, variogram analysis and Cross-correlation technique are used for the spatial dependence analysis. The correlation methods are used to characterize and visualize the spatial clustering or dispersion in the selected domain. The analysis results indicate that there is a clustering of significant wave height over the selected domain of the Northern Indian Ocean.