That is +15C. I have noticed that performance is affected already at temperatures below room temperature to become really bad when nearing or passing below zero and I wonder if any brand is better than others regarding outdoor temperatures.
Obviously non-rechargeable lithium batteries are a must in really cold temperatures, but do any rechargeable NiMH AA batteries stand out as better than others when the temperature starts dropping below 15 degrees?
My only experience from altimeters is a five year old Suunto which had bad GPS-reception and poor altimeter which gave me very varying distance and elevation data on the same route. It didn't instill any confidence for using the altimeter for any purpose except perhaps to detect a change in the weather.
I will be getting an iPhone 6 in a few weeks time which has a built in barometric sensor, I am looking forward to see how well it performs and I will report back when I've tried it.
@captain paranoia: What about the Jetboil Joule? It has the canister upside down, and it is placed under the burner. Looks like it might deliver decent cold weather performance.
I'd like to add Mountain Hardware to the list of manufacturers with waterproof rucksacks. Their OutDry models use a waterproof inner membrane making them look and feel the same as normal rucksacks.