Easy one, "people" definitely.
Living in a climate where the four seasons are winter, still winter, thaw, and construction(these are what people here joke about, we do have nice fall and spring. ) taught me how to adjust and cope with the severe weather.
Although, I've never been hit by a hurricane or a tornado, and it's hard for me to imagine how much stress they cause on people.
I guess I'm more picky with people especially if I have to be around them for a long time. I get stressed out when someone is being rough with objects, freaking out over easily fixable problems, or chewing my ears off with gossip. On the other hand, some people put me in a great mood, too.