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The glacial meltwater streams in the McMurdo Dry Valleys (MDVs), Antarctica only flow during the austral summer and contain abundant algal mats which grow at the onset of flow. The algal abundance in stream channels of this polar desert make the streams biogeochemical hot spots. The MDVs receive minimal precipitation all in the form as snow, which is redistributed by wind and deposited in distinct locations that become persistent snow patches each year. Previous studies identified that MDV streamflow comes from a combination of glacier ice and snow, although conventionally, snow has been assumed to contribute little to the overall water budget. We used a combination of satellite imagery, terrain analysis, and field measurements to determine where snow patches accumulate and persist across MDV watersheds, and to quantify the potential hydrologic and biogeochemical contributions of snow patches to streams. Watersheds near the coast have the highest snow-covered area and longest snow persistence. Many of these snow patches accumulate within the stream channels, which give opportunity to directly contribute to streamflow. During the summer season of 2021-22, on average, the inputs from stream channel snow patches to streamflow was between 12-25% of the annual discharge, as determined by snow area and SWE. The majority of the watersheds had higher nitrogen and phosphorous concentrations in the snow patches than streamflow, and six streams contained snow with higher N:P ratios than the average N:P in the stream water. This suggests that if these snow patches melt early in the summer, the nutrient and water inputs from snow could occur at the right time and stoichiometry to be crucial for early season algal mat growth.