Here is a calculator I found online to see about what the power loss is at altitude and humid conditions.

http://wahiduddin.net/calc/calc_hp_dp.htm

To find the values to plug in go to www.weather.com and type in your zip code.

At two of the flying sites that I fly at my engine outputs for today are 74.9% to 84.2% rated power at standard conditions. Now that's why a lot of us high altitude fliers go a little bigger on the engine size, even voiding the product warranty to get a plane to fly like it would at lower altitudes.

I love the variable seasons here, but you need a variety of toys to enjoy it all. Boat, snowmobile, 4 wheeler, golf supplies, skis, SUV, model planes......on some days you could use any one of them and not have to drive more than an hour or two from home. I'll never move because there is never a boring weekend around here.