We used to fly in Idaho in the summer. 3000 or so feet sea level, 100+ degrees, about 6% humidity and dead calm. We used big props and very large venturi and lots of fuel. We'd go to Seattle for a contest: 65 degrees, a bit of breeze, humidity in the 60s or so and of course, at sea level. It was incredible the difference in how the planes handled and the difference in fuel load needed.