Supercooled water is found to have a significantly enhanced freezing temperature during transientelectrowetting with electric fields of order 1 V/lm. High speed imaging reveals that the nucleationoccurs randomly at the three-phase contact line (droplet perimeter) and can occur at multiple points during one freezing event. Possible nucleation mechanisms are explored by testing various substrate geometries and materials. Results demonstrate that electric field alone has no detectable effect on ice nucleation, but the moving boundary of the droplet on the substrate due to electrowetting is associated with the triggering of nucleation at a much higher temperature. VC 2015 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4938749]