Which factor affecting climate most influences the climate of northern south america?

The height (altitude) of the Andes influences temperatures. Temperature falls with altitude, so temperatures on the high plateaus and mountains are much lower than on the plains which lie on similar latitudes.

places of higher salinity. there are parts of the ocean where hardly any rain falls but warm dry winds cause lots of evaporation. this evaporation removes water – when water vapour rises into the atmosphere, it leaves the salt behind, so the salinity of the seawater increases. this causes the seawater to become denser.