I've had mine leak from the radiator hose clamp above the thermostat housing. It's not easy to get to, but if you are lucky you can get a long screwdriver or a socket on a long 1/4" extension. If you're unlucky, you have to remove the ad to get to it.
If you determine that is the source of the leak, and you have to remove the rad to get to it, I suggest installing a new wider hose clamp as opposed to the POS thin one Honda used. This results in higher clamp load and less chance of future leaks. Also try to position the screw so you can reach it with out removing the rad.
Mine did the same thing. After I tightening the clamp it hasn't leaked. It would do it only in cold weather.