Does altitude make a difference?

I know this question has been asked before, but after reading of the Peruvian side Union Minas, who are apparently the professional side that plays at the highest altitude in the world, it got me thinking.

Each city does have an altitude figure in the editor, and as that isn't visible in the game, if it doesn't affect teams performances at altitude, why is it there?

Can affect weather but otherwise there's no reason, also you can find a clubs latitude and longitude by using the editor.

It most certainly does. I managed as Argentina for a while, and in World Cup Qualifying, visiting those South American teams which IRL play at high altitudes, I noticed that my side's Condition dropped much much more than it would in a "normal", sea-level match.

It wasn't uncommon for me to end up with everybody but the centre-backs and GK on less than 50% Condition; I actually started modifying tactics just to try and conserve energy (less closing down, fewer forward runs, etc) as the final minutes with an exhausted team were just awful to watch.

Also, played a World Cup in Mexico, and the Mexico City games were quite similar.