When cooking with canister stoves, there are a number of factors that must be held in tension: Air temperature, fuel temperature, type of gas (butane vs. isobutane and propane), elevation, canister chilling, etc.

I've just written a post where I try to tie these things together in a succinct and hopefully practical fashion. Have a look if you like at: Canisters, Cold, and Altitude: Gas in a Nutshell

HJ