I think the biggest factor in my location is not weather but rather the amount of stress I put on the chain. That stress comes from a lot of climbing and a lot of hammering. That stress translates to a lot of stretching and thus the measurement thing.

The other thing is the Dura Ace 7800 that I use. The chain is not as wide as a 9 gear cassette Ultegra that I have on the other bike. So I was told there is more stress on the chain for that reason.

Maybe the other reasons for non weather chain wear are the rider's mis use of the gears, not matching the front ring with the rear gears. That would cause unnecessary stretching. Another might be allowing the chain to be without proper lubrication for a spell.

On the lube thing, I use two types of lube. One is actually to clean off the chain and the other is to keep the lube onto the chain for a longer period of time.

For the question on the 10 gear Shimano, I use the Dura Ace chain for the 7800 that I have.