If the water in the water pipes is not flowing at least a trickle then yes the water pipes that are exposed will freeze at 25 F degrees.
If you have exposed pipes they can freeze at even 33 F if the water pipes are not protected and the water is not flowing.
If the wind is blowing the wind chill will also freeze the pipes much sooner as well.
So if you have exposed water pipes make sure to insulate them if possible and leave the water on running slowly so that the water can continue to flow.
Water that is flowing has a less chance of freezing than water that is sitting still in the water pipes.