Understanding the factors that affect species’ distributions is a central topic of ecology and biogeography. However, the majority of research about this topic has focused on species inhabiting terrestrial environments. At broad scales, abiotic variables consistently serve as the primary determinants of species’ distributions. In this study, we investigate the explanatory power of different abiotic variables in determining the distributional patterns of sea snakes on a global scale. Additionally, as the boundaries of realized thermal niches have significant implications for the ecology of the species and their geographic distributions, we also evaluated the asymmetry of realized thermal limits (i.e., differences in variances between upper and lower limits of the realized thermal niche). We obtained global environmental variables and occurrence data for each species across their entire known geographic range. Using this data, we employed a correlative ecological niche modeling procedure to analyze the influence of individual variables in explaining species’ distributions. To estimate the realized thermal limits of each species, we extracted the mean, minimum, and maximum values of temperature at four depths (superficial, mean benthic, minimum benthic, and maximum benthic) for each occurrence record of the species. We then evaluated the asymmetry of the realized thermal niche by measuring and comparing the variances of the upper and lower limits. Both analyses (the importance of variables and realized thermal limit asymmetry) were performed at three taxonomic levels (sea snakes as a lineage of marine-adapted elapids [true sea snakes + sea kraits], subfamily, and genus) and at two spatial resolutions. Overall, we found that temperature, phosphate, nitrate, salinity and silicate concentrations were the most influential factors in explaining the spatial distribution patterns of sea snakes, regardless of the taxonomic level or spatial resolution. Similarly, we observed that the realized thermal limits were asymmetric with higher variance in the lower limits, and that this asymmetry decreases as the taxonomic level and spatial resolution increased. Finally, our results align with previous findings regarding patterns of asymmetry in realized thermal limits and the significant influence of abiotic variables in explaining the distribution of marine species.