Journal
Photographing Bali in the wet season
The Bali wet season runs from about November to March, peaks in January and February, and is the period almost every photography workshop, tour and holiday deliberately avoids. It is also, for anyone photographing people rather than landscape, the most interesting time of the year to be there.
The avoidance is understandable. It rains, sometimes for hours, sometimes hard enough to flood a road in twenty minutes. Humidity sits around ninety per cent. Equipment fogs, sensors get damp, and the reliable blue-sky sunrise that sells a photography tour simply does not turn up for weeks at a time. If your subject is a rice terrace at golden hour, the wet season is a bad investment.
If your subject is people, the calculation inverts entirely.

What rain does to a place
Rain changes behaviour, and behaviour is what documentary photography is made of. People shelter, cluster, wait, improvise. Plastic ponchos come out in colours no designer would have chosen. Traffic slows. Ceremonies continue — the Balinese ritual calendar does not pause for weather — which means you get processions in the rain, offerings carried under umbrellas, priests working in downpours, and congregations kneeling in standing water.
None of that exists in August. The dry season gives you the same scenes performed under a flat blue sky with everybody comfortable, and comfortable is rarely photogenic.
The rain also does something to the surfaces. Wet paving reflects. Wet skin reads differently. Colours saturate. The light under heavy cloud is enormous and soft and comes from everywhere, which is unflattering for landscape and extremely good for faces.

The light, specifically
Wet season light divides into three states, and they are all usable.
Pre-storm. Half an hour of very strange yellow-green light as the cloud stacks up. Short, dramatic, and the closest thing to free drama the weather offers.
Under cloud. An enormous soft box, two or three stops down from open sun. Even, directionless, and completely reliable for hours at a time. This is the light most portrait photographers pay to construct.
The break. The twenty minutes after rain stops when the sun comes back onto wet ground. Everything reflects, steam comes off the road, and people come back out. If you have packed up by then you have missed the best of the day.
The one thing you rarely get is the clean, contrasty, hard-shadow light of the dry season. If that is what your work depends on, do not come.

Keeping the camera alive
Weather sealing is a marketing term, not a guarantee. Assume your camera is not waterproof and plan accordingly.
Condensation is the real enemy, not rain. Moving a cold camera from an air-conditioned room into thirty-degree, ninety-per-cent-humidity air will fog the lens, the viewfinder and — over time — the inside of the lens where you cannot reach it. The fix is to stop air-conditioning the room your camera sleeps in, or to seal the bag before you go inside and let it warm up before opening it. Silica gel in the bag, replaced regularly, is worth the trivial cost.
Rain covers. A proper one is better than a plastic bag, but a plastic bag and a rubber band works and costs nothing. Carry two.
Microfibre cloths. More than you think. They stop being useful once damp, so bring several and keep them sealed.
Changing lenses. Don't, if you can avoid it. One body, one lens is a sound wet-season strategy for reasons that have nothing to do with aesthetics.
Footwear. Sandals. Anything that holds water is worse than something that lets it through, and you will be standing in it.
Practical realities
Flooding is localised and fast. Denpasar streets and the low-lying parts of the south can go from dry to shin-deep in half an hour and drain almost as quickly. It is rarely dangerous in the city; it is genuinely dangerous in river valleys and on the coast, where flash flooding and rips are a real risk after heavy rain.
Roads in the mountains — the route up to Munduk and Bedugul in particular — get landslips. Journeys take longer than the map says.
Mosquitoes are worse. Dengue is present in Bali and peaks in the wet season. Repellent is not optional.
On the other hand: fewer people, lower prices, and every site you want to photograph is emptier. Tirta Gangga in February is a different place to Tirta Gangga in July.

Nyepi
The Balinese new year usually falls in March, at the tail of the wet season, and is worth planning around in one direction or the other. The day before is Ngrupuk, when villages parade enormous ogoh-ogoh demon effigies through the streets and burn them — one of the great photographic events anywhere.
Nyepi itself is a day of total silence. No lights, no travel, no work, no leaving your accommodation. The airport closes. Streets are patrolled to enforce it. As a photographer you will not be working, and attempting to is both illegal and a genuine offence. Plan for it as a rest day.
The honest summary
The wet season is harder, wetter and less comfortable, and it will produce a smaller number of usable frames per day than a dry-season week. The frames it produces are less like everybody else's. Whether that trade is worth making depends entirely on whether you are trying to photograph Bali or trying to photograph what happens there.