If it’s sunny and dry but cold, is it harder to start a fire than in equal but warmer conditions?. Empirically it seems so, but I couldn’t say why. Given that flames are in the range of 400-500 F, you wouldn’t think that having the air be 20 instead of 75 would make that much difference. Or does “dry” wood retain more moisture when it’s cold?
The fuel needs to be brought up to combustion temperature. If the wood is cold, ISTM that it would take longer to light.
Does the wood have bits of snow or ice stuck to it? It usually will, in winter.
I did the math once and came to the conclusion that it takes an extra 12% of energy to get a fire started. You can decide for yourself if that’s significant. I think it is.
I ask because I was testing my firestarting skills today and was confounded by thin, dry(?) pine twigs refusing to light. But if dead branches on a tree aren’t dry kindling, what the hell is? I’m wondering if cold weather somehow dampens what would otherwise be suitable tinder and kindling in warmer weather.
Unless you live in Panama or Venezuela or some-such place.
It’s an interesting question. I think it’s right to say that fire starting relies significantly on transfer of heat from the ember and the tinder/kindling, so if those materials have a greater capacity to absorb heat before they become incandescent, it becomes more likely that the ember will die first.
On the other hand, tinder material may be drier in icy conditios, as, even if it was frozen wet, the ice will sublimate away into the dry air.
I have started fires outdoors in temperatures as cold as -30c. It is essentially no more difficult to light a fire than in warm weather. Tinder lights just as fast for all appearances in colder temperatures, perhaps because most tinder is of very little mass. I often use wax/sawdust fire starter and though it is much more dense than say paper it was still easy to light.
You have to use fuel that is dry and not covered in snow and ice. You get such fuel from the same places you would in summer if you want dry fuel. You have to build a dry base for the fire to start on. We would often be building it on a base of evergreen branches sitting over deep, deep snow. The fire slowly melts a pit as it burns. Butane lighters need to be warmed in your hands a little first (or if you are thinking kept in a pocket close to your body) or they will not produce much of a flame. Matches work normally.
Any ideas on why dead, apparently dry pine twigs taken off the tree would sullenly smolder instead of lighting?
Because they weren’t dry. If they are still on the tree, they are not as dry as twigs that have fallen. In cold weather, a not dry twig will snap like a dry one.
Cold weather is one thing. But whatever you do, don’t use your last match to start a fire without checking to see if it’s under a tree with snow-laden branches.
Current winter camper here chiming in.
Frozen fingers and frozen BIC lighters and wet tinder do not play well with each other.
To answer the OP question, even dead tree twigs will absorb moisture from recent snowfalls. And will never light until you can somewhat dry them out over another flame.
My advice is to plan ahead. Fill a gallon zip-lock bag of drier lint (!). Got some sawdust? Bag it. Itsy-bitsy birthday cake candles can be gently laid upon your small flame to help with wet tinder.
Barring that, start small. Once out in the field, harvest the driest grass-type tinder you can find, peel little strips of bark off of trees - birch bark (if dry enough) is a good secondary fire-starter. Even wet pine needle branches, once dried out enough will help get your tinder/twigs going enough to start bigger branches.
Gather the driest tiny twigs you and find. This will be your tertiary fuel once you have a flame going.
Do not smother by adding more fuel. Keep that flame going no matter how small.
If all else fails, book the hotel room down the way. 
Unless those fallen twigs are under 2 feet of snow. 
You can tell a dry dead twig on a tree from a wet one, so I respectively disagree.
I’ve always heard it the other way around: ground stuff will always be damp.
I thought it must be something like that. So if you must, carry or gather enough tinder to keep a tinder fire going until you can finally dry out some kindling enough to catch. Got it.
I’m having this idea for a Warner Bros. cartoon: Daffy Duck has a huge pile of sawdust, soaked in gasoline, along with some nitrocellulose flash powder and some napalm and thermite, with a 10,000 volt igniter- which makes a small sullen puff of smoke. Meanwhile, Bugs Bunny strikes a single spark which instantly starts a yule log blazing. Cue Daffy turning red and steam coming out his ears.
Not to hijack the OP, but just had a weird thought regarding this scenario.
OK, it’s below the freezing point.
We have learned that fire-starting is not dependent upon ambient temperature. Wet fuel bad, dry fuel good.
Hypothetical:
- Need to start fire in cold weather with wet firewood/tinder.
- Girlfriend needs warmth. Looks to her caveman to provide.
- Efforts to start fire fail.
- Caveman notices girlfriend has aerosol bottle of hair-spray in bag.
- Instant flamethrower/fire starter!!!
Feasible?
Sorry for hijack…
:dubious:
Cite? What math? 12% extra above what? 12% extra from NOT lighting a fire?
Generally curious to fight my ignorance.
or are we being whooshed already
The spray pattern of hairspray doesn’t produce an incredibly hot flame (don’t ask me how I know). But there’s a lot propane or butane in those cans you’ll certainly dry a reasonable amount of tinder with it. If you don’t have dry wood to sustain the fire your warmth might run out when the can is empty.
Bolding yours.
Now you gone and done it. I have to ask you just how you know. 
Same way I know. 
Same answer, too. You’ll get quite a blast of fairly low-temp flame that will probably blow your tinder all to hell and gone before it ignites anything, and will run out before anything bigger ignites. It would, however, be adequate to light a drier branch of still attached but dead pine needles.
Ahh, to be young, drunk, invulnerable and possess all the above and a dead Christmas tree. Luckily we did the experiment in the driveway.