Question on overheating

I need some suggestions on what the most likely cause of my car's problem is. For the past week or so, here's what's been happening:

I'll start the car up and get driving around town (40- 50mph, stop and go), and if I leave the heat on (even on the lowest setting), the car won't warm up all the way, the temperature needle stays a tick or two below where it usually gets to when the car is warm. If I get on the highway and cruise at a steady 70 mph or so, the temperature needle pretty quickly starts moving up towards hot. When I crank the heat on full blast, the needle will move down real slow, but the car will still run hot.

When I checked the engine after I parked, here's what I found: The upper radiator hose is hot, but the lower hose is cold. The cooling fans don't come on automatically like they should, but I know they both work because if I turn on the a/c, they'll both kick on right away.

About one year ago I changed the thermostat and gasket (with new Honda parts) and flushed and filled the entire system with fresh antifreeze and water. The mixture still looks good, it's not discolored.

Other than this cooling problem, the car runs fine. I'd appreciate any suggestions you guys could give.

Check the temperature switch. It might be bad and not turning the fan on when it reaches the certain temperature.
On EFI, there are two, one at the bottom of the radiator, another on the thermostate housing. Since the fans turn on like you mentioned, then this should be your problem. About $20 at the store, get it fix soon. And get Honda part for this, aftermarket sensors switches on abit later than oem. But honda switch is $30-40 and not returnable :(. Maybe go to a junkyard.

You should check the thermostat anyways. I had installed a new one and disregarded it when I started to have some more cooling problems. Turns out it was stuck! and I only had it in for about 2 months. If you try what anchovies mentioned and you still have a problem, check the thermostat just in case.

yeah id check the thermostat, just change it

Thanks for the help. I'll change both the thermostat and the temperature switch and see what happens. But if it is the thermostat, wouldn't the upper radiator hose be cold because the thermostat would be stuck closed, not letting the hot coolant flow to the radiator?

No the top one would be hot. But since its not flowing properly throughout the engine, the bottom one would be cold because it isnt getting any of the "used" coolant there.