Car power steering is hard in the morning?

I have Honda civic 1999 in good condition. When I start the car in the morning drive the power steering is very very hard needs too much force to turn my car. But after a drive of one hour to my office it becomes normal when it gets hot. I have checked the power steering fluid and belt both are good. What could be the reason; a bad pump or anything else? Kindly share

Added (1). please update

Could be air in the system

That could be a worn steering rack or clogged pipes

You checked the fluid but have you ever replaced it? Suck as much as you can out with a turkey baster, then refill to proper level with the correct fluid. Drive it and do it again the next day.