We have a couple of questions showing that in dry times a flare can start forest fires.
- Is there a safer way to use a flare in a wooded area?
- What is the risk of starting a forest or wildland fire with a flare gun?
Most flares will start easily when wet and even burn underwater. So would seem a tempting fire starting tool.
I am wondering about in wet times, if a flare would be effective for starting fires. Flares burn pretty hot 1,600 °C (2,900 °F) and I suspect that might actually make it more difficult to light a fire with wet wood/kindling.
We have some related questions, but they don't address flares.
- Is it possible to use a flint and steel with wet tinder?
- Given limited space and weight what should I carry to get a fire going with damp wood?
- How to light a fire with wet firewood?
Edit
When I wrote this question I was thinking about road flares, that are mostly fuel and no launch system or propellant. It was not until some new activity that the possibility of using an airborne signal flare that I even considered the possibility. It seems like each of the answers have existing have specific types of flares in mind. Answers should probably includes specifics about the type of flare they discuss.