What needs to be fixed? Buick Century running hot.?

2001 Buick Century with 180,000 miles runs hot. By hot I mean the temperature gauge climbs above the half-way mark while driving at highway speeds. In stop-and-go traffic, the needle approaches the red “hot” bar.

Fluids all check fine and full. Belt is not cracked. Hoses are not cracked. There is a slight whirring sound that raises in pitch I notice while driving on the highway. Seems to be coming from the front of the car.

Any thoughts as to what I should check or replace? Thanks.

Popular: What may have caused the hydraulic jack reservoir to crack on my RV? How crazy is it to drive an old Rolls Royce? Which of these 2 amps will better run my subs? Can bad rocker arms cause the transmission to change roughly? How would one fly across the border with a private jet?
More: 2005 Mistubishi Adventure Stereo AUX? Is this car a good deal? Please help :(? Why isn't my sub loud? Renewing drivers license in another state? Car accident?