Water coming up through cellar drain 😬

[BarbaraOcumbungles]

1930’s house with small cellar which has a drain with a trap in the lowest corner. We’ve lived here 2 years and the level of water in the trap has never changed. I just swill it out periodically or it smells stagnant. Since it snowed we’ve had water coming up the drain, it isn’t dirty water, doesn’t smell of sewage or anything but there’s quite a lot of it, maybe 3 inches at the deepest point and up to an inch up the bottom step. Is this just one of those things and we’ll need to wait for it to drain away naturally or should I call a plumber?