Northern PowerGrid is working to restore power to more than 840 properties across the YO1, YO10, YO3 and YO31 postcodes.
The power cut was reported at 10:25 this morning (16 August 2019).
Walmgate Bar traffic lights are out and motorists are being asked to approach with caution.
In addition, many of the stores on Foss Islands Road have been affected.
Northern PowerGrid have said they expect to resolve the issue by 12 noon.