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I can't really say about your location however IMO you should switch over to PVC and get rid of bell boxes to neaten up a bit.

The other issue I belive that when someone install them they were not really watching the gasket when they install the luminaires. which that is pretty common failure if not installed properly or gasket get dry or get brittle and let water seep in.

Drill the glass bottom IMO it can be done otherwise lexan verison is easier to drill out { but watch the wattage rating on them }

So there are few ways you can do this the key issue is find a way to prevent any more water pentration and have proper drain fitting or drill the drain opening as need to.

Merci,
Marc

Many Thanks Marc.

The location could be underground, since this arbor soaks in the rain, and takes days to dry.

Yes, PVC to NM conduit body would be a much better design. The metal Bell boxes also disintegrate rapidly in this area.

Thanks for describing the vaportight gasket issue. Gasket, box, & fittings could be tested by removing jars to a water bucket.

Drain holes only for stubborn condensation makes sense, since water leaks can fault, needing repair or replacement.

Best regards to you & yours.

IMHO, water is going to find any point of entry into these fixtures, no matter what you do from what I can see in the pics. The 'raintite' EMT connectors are raintite....not waterproof.

Judging from the pic, that water did not enter quickly, as it is dirty/discolored.

You may achieve a 'better' install by having conduits enter the fixture base box directly, as opposed to the top entry.

I came accross some classified location (explosion proof) fixtures that were submerged in a wet well pump station (sewage) that were half full of liquids; that seeped in via the threaded (min 5 threads) and the fixture bodies. Water finds a path!!

The water is coming directly out of the air -- not rainfall.

Folks, what happens is that the interior gets very warm and drives air out.

Then the lamp is turned off and the jar space cools.

It cools so much that it forms a vacuum effect and draws in moist air.

The vapor condenses at the bottom. The heat from the next cycle is not enough to drive off the water from the prior cycle.

Day by day, cycle by cycle the jelly jar fills up. Even WP gaskets are not enough to stop the condensate build up.

The only solution is to avoid this orientation -- or to provide a bleed hole in the jelly jar. A very touchy thing to pull off.

You'll see variation on this in cold and chiller boxes. You can slow things down, but the condensate just keeps coming.

BTW, treat your wirenuts as if they were below grade in such installs. Dip them in epoxy.

The space fillers in the box are also not vapour or water proof. the back box can allow water in via the hub where the emt and connector screw into the box.
If not located in a hazardous location a small hole big enoug to let water out and ants in can work for condensation.
Drilling holes in glass is a bugbear and don't bother if the glass is tempered. it will just break if you drill.

Tesla makes an interesting point. If that is the problem, it can be reduced somewhat by getting the moisture off the top of the box.

There are replacement globes available - they're pretty interchangeable between brands, unless you get the $8 box store specials - and some are even made from plastic.

This is worth noting, because many are of tempered glass, and those will instantly shatter into glass 'gravel' the instant your drill bit pierces them. DON'T DRILL GLASS.

In a location like this one, you're in a no-win situation. Add a drain hole, and the thing fills up with gnats.

Your best solution might be to completely do away with the globe, but keep the cage. Then, use a bulb that is outdoor rated. Outdoor-rated PAR bulbs are common, and the 'halogen' bulbs have a heavy enough glass that they just might work. The cage will just help keep flammables (like leaves) from touching the hot bulb. There might even be outdoor-rated CFL's.