Are there degrees of wetness on tilled dirt?

Do tilled hydrated dirt blocks have invisible degrees of wetness that dictate how fast the crop will grow, or is every hydrated dirt block at the same level of hydration? For instance, is a hydrated dirt block four blocks away from the water source less hydrated than one right next to the water source? Similar to how redstone wires lose power the farther they get from the power source? Or are they all the same as long as they're hydrated?

PS I'd like to know for both versions