My steering is stiff - 97 Crown Vic?

I have a 1997 Ford Crown Victoria LX and recently moved to Washington from California. We had a major wave of extremely cold weather, but it has begun to thaw enough for me to drive. I've noticed my steering is stiff and slightly harder to turn than usual. I know my power steering is still technically working, but I'm used to ery soft steering that can be controlled with a single finger. After the cold weather, the car hasn't felt the same. What should I do? Thanks.