too much is a problem... overly moist will increase risk of bud rot and other infections. Too much weight can cause physical damage to the plant.
2 summers ago i tried an outdoor grow in my backyard... not enough light, but that's a different story.. anyway, august and september were humid and rained often... i ende dup haveing to cut off some colas with initial infection of bud rot...
So, just inspect them well... If it's raining constantly, a fan on them after it ceases can help evaporate that water faster... outdoor fans that are powerful like that are very expensive, though. but, anything that reduced length of time they are wet will help... and wouldn't worry unless it's happening at an unusual frequency.