Sodium-metal batteries are an attractive energy storage technology, owing to the low cost and relative earth abundance of sodium. However, despite the importance of electro-chemo-mechanical phenomena in alkali-metal batteries, experiments on the mechanical properties of metallic Na are relatively scarce, especially in terms of its viscoplastic response. In this work, we measured the temperature- and rate-dependent deformation of sodium by performing tensile tests in inert gas environments. Digital image correlation measurements were performed to track the local strain and rotation fields. Temperature-dependent experiments were used to experimentally calibrate the activation energy for creep. Furthermore, local deformation measurements of sodium suggest that grain-size and crystallographic orientation effects may be important considerations for sodium-based batteries. Finally, the implications of creep on the performance of Na-metal batteries discussed, providing guidance for future modeling efforts.