Starting a fire can sometimes be hard enough when it's dry, let alone when it's tipping it down. But when it is, what steps should you follow to try to ensure the fire gets going successfully?
I'm talking about the process of gathering firewood when it may be damp, to start a fire in the rain - assuming basic things like matches are available but not much else.
When building a fire in any weather condition you need some kind of starter. If you are expecting to experience wet conditions a great planning step is to store some starter in a waterproof location. If you don't have any household material, then gathering kindling and storing that will work. When backpacking I keep a small water-proof cylinder with a lighter, 2-3 strike anywhere matches, and some tightly rolled newspaper.
You'll also need larger pieces of wood to sustain the fire. Eventually your fire will be able to handle wood that is slightly damp, but you'll need a few decent pieces of dry wood to build up a base of hot coals that can then be used to help dry wood later. The best way to accomplish this in wet conditions is to look for naturally piled up wood or big thickets. Underneath a fallen tree can be a great place to find some medium sized sticks that have been shielded from the rain.
As for starting the fire, you will most likely need some kind of cover. The amount of cover depends on how bad the rain is. At a minimum you'll need good cover when starting the fire, and depending on conditions you may be able to fully uncover your fire once it is started. This is where all the big warnings need to be posted though! The cover over the fire could itself catch fire, creating a dangerous situation. The cover could block fresh air, which obviously is dangerous around a fire, not to mention bad for the fire as well. The few times that I have needed to start a fire in a very light rain, I simply used by body as cover for the kindling, and once that was going an occasional drop of rain wasn't a problem, never tried in a heavier rain though.
The last item I would mention is placement. Especially if you are quickly getting your fire going as rain starts, make sure to pick a place that will not get washed out if the rain intensifies. If you are using a fire pit this shouldn't be a concern.
As with all fires, you need more tinder and kindling than you think. In dry conditions I once heard the advice of "get as much as you think you need, then double it". In wet conditions, I'd suggest you triple/quadruple the amount of kindling and triple the tinder.
Specifically, take the tinder and get it out of the rain as soon in your firewood gathering process as possible. Give the tinder as much time as possible to dry out a bit.
Build the fire, but put some sort of tarp or cover over top of it until it is caught. I'd recommend getting 2 friends to hold a poncho horizontal at shoulder level, and then take a few side-steps once the fire has started. If you are alone, tie the tarp overhead and get it out of the way as soon as you have strong flames on the kindling.
Once the fire is lit, set up a small pallet with some of your fuel/kindling to get and keep the wood you are planning to burn off of the ground. also keep it as near the fire as you can safely. The heat will help to dry out the wood before you put it on the fire (but some of it will be wet).
Some tricks to make lighting a fire in the rain easier:
From the answer to this question here: Given limited space and weight what should I carry to get a fire going with damp wood?
One technique that I'm surprised hasn't been mentioned yet is using a small wax candle. If you search for "tealight candle" you'll see what I'm talking about. Lighting a candle with a lighter makes it much easier to get kindling started compared to using a lighter alone. What's especially nice about using a candle is that you can get many, many uses out of it whereas most easy firestarters like lint+grease are one time use.
GASOLINE!!!
Back "in the day" we would always look for birch bark (as it burns when wet) and/or toss a little white gas from the stove onto the fire.
