The influence of aspect with respect to the sun is most important at mid latitudes, say from about 30 degrees to around 55 degrees--from about the southern U.S. border to about the northern British Columbia border. At equatorial latitudes, the sun goes almost straight overhead, which shines equally on all slopes. At arctic latitudes, in the winter, the sun is too low on the horizon to provide much heat and when it finally gets high enough in the spring and summer, it just goes around in a big circle anyway, shining on all the aspects with nearly the same intensity. Thus, in the arctic spring, aspect has some influence but not nearly as significantly as in mid latitudes. Therefore, the importance of aspect is primarily at mid latitudes.