<p>The Red Sea is a marginal sea characterized by high evaporation and thermohaline circulation, which are driven by interannual to centennial climate variability. The North Atlantic Oscillation (NAO) is a primary driver of wintertime sea surface temperature (SST) in the Red Sea. Yet, few studies have examined the stationarity of the NAO-Red Sea SST relationship, limiting our understanding of interannual SST variability and its impact on critical ocean processes. Here, we analyze satellite and reanalysis data to examine the dynamics and stationarity of the NAO-Red Sea relationship. Sliding correlations with five-year windows between the winter-averaged (Dec.–Feb.) NAO index and satellite SST from the Red Sea reveal a temporally nonstationary relationship, while spatial regressions reveal a spatially nonstationary relationship. Regression of sea level pressure, meridional and zonal wind, and 2-meter air temperature from reanalysis products onto the NAO index indicate that periods of significant negative correlation are associated with a zonally expanded Azores High. Conversely, periods of insignificant correlation correspond with a contracted and displaced Azores High. Composites of strong and moderate ENSO events indicate that asymmetric decreases in sea level pressure in the Atlantic during strong El Niño events may explain the sea level pressure patterns observed during periods of insignificant NAO-Red Sea SST correlation. These results emphasize the importance of considering interacting climate modes and their evolving teleconnections to understand future Red Sea SST variability, which has implications for regional ecology, economic activity, and ocean processes in other basins.</p>