This is long. Please bear with me.

During a recent heavy rain, my husband and I started smelling a mildewy smell in our kitchen. At first we got panicky and thought our roof might be leaking -- my husband climbed around in our very tight, cramped attic to check for leaks. That was an adventure! No leaks were found.

We managed to narrow down where the smell was coming from -- a smallish (4' long) specific cupboard -- so then we got concerned that the shower behind that wall might be leaking. It seemed unlikely, since the area where the water pipes are is on the other side from this wall, but you never know. We tried to pull the cupboard from the wall after unscrewing it, but no luck there. So, having no other options, we just drilled some small holes in the cupboard to see what was going on underneath (they have sliding drawers, so the cupboard will still be usable. And we'll be redoing our kitchen in a couple of years, so it's not a biggie).

We could find no obvious cause of the smell -- no signs of wetness, black mold, or anything else obvious -- but it's very clear that the base of this cabinet is where the source of the smell is. Here's what I think is going on:

The previous owners of this house had a major water leak in the kitchen at some point. You can see the water damage all around the base of most of the cabinets. This specific cabinet is actually somewhat dark in color at the base, so maybe it's mildew. When you look through the holes that we cut, you can see the old water damage, and a little bit of mold on the interior of the inside of the cabinet, but the most obvious damage is on the outside, where again, the cabinet is discolored, and dark in some spots.

I have no idea why there would be no smell for the past year that we have lived here -- could the heavy rain and generally humid weather that we've had for the past week or so have caused damp, humid conditions that caused the mold/mildew to reactivate at the base of this cabinet? I live in Southern California, so things are usually quite hot and dry here, which might have kept the mildew from getting too active until this "rainy season".

Reality: we can't replace the cabinets at this time. Simply pulling it out and doing without is not really an option, either. This is a very small kitchen, and we need all our cabinets. We will be redoing the kitchen in a couple of years. My question is, what can I do about this smell, if anything, temporarily so my kitchen doesn't smell so bad? My thought was to run the dehumidifier in front of the base cabinet base for several hours, and then perhaps wash the cabinet down with bleach, but I'm not sure if that would actually do anything.