The horn beeps by itself randomly and without warning while the ignition is turned on - the car can be idling or in motion when it happens. Sometimes it doesn't happen at all during my journey, while at other times, it starts maybe 10 mins. into my journey and continues on and off - even when I am stopped at a red light.

Although I can't speak to the root of the problem (may be only the horn, or also involving the car alarm system), I suspect that the outside temperature
is influencing this situation. The problem originally started last mid-October, then stopped in early December (no beeps at all during the winter), but started up again half a month ago (coinciding with a rather warm spell in Toronto, where I live). Is it possible that a wire or some such near the horn, that would have been contracted in cold winter weather, is now expanded due to the warmer weather, and is somehow setting off something in the horn?

The Honda dealer who checked it yesterday said it may be the hood latch. They disabled the part of the car alarm connected to the hood, but the beeping has continued.

I am now at wits' end.

Many thanks for any suggestions you may have!