I planted oats a day before forecast rain. It rained, but no downpours. I checked plot the day after rain and there was still a lot of oats visible on top of soil. Does anyone know if the oats will still grow?

It will grow, give it time.

Might want to consider covering or packing down the oats into the ground, giving the seed a better chance at germinating then sprouting! This might speed up the process as well.