Installing lights outdoors,

From my experience it was never a good idea to install an old 60 or 100 watt bulb, why because they would explode if they got wet.

Then you have to ask did they light up old Christmas decoration outside, back in the days when the lamps where dipped in highly flammable paint to create various colours as required, they didn't explode.

I installed a bunch of "string lights" a couple months ago and they have open E27 lamp holders with LED 5 watt bulbs.

What do you think about installing open lamp holders outside in the rain?