Car does not start in the rain

my 1999 Honda Accord will not start if it has rained or snowed heavily. The battery is new as are the spark plugs. Once the car drys out (I can do this with a hair dryer) it starts without a problem. I have no problems once it has started. The mechanics cannot find anything wrong - when they hook it up to diagnostic equipment. I appreciate any ideas about what might be wrong.

Bad spark plug wires, bad distributor cap and rotor. You have a problem with moisture getting somewhere, and letting the spark energy leak out. These items are easy to change and not very expensive. I’d start here.

Busted has nailed it. Do the wires, cap, rotor and plugs. Wait 'till you see how good the Accord will run afterwards. Rocketman

there is a thing call MAP sensor it adjust fuel and timing for weather and allitute. it might be sending a wrong signal to the computer and the timing is wrong with the fuel. when it is warm or dry the map sensor is stuck for this condiction