There are three primary factors that contribute to Alaska's Climate
Covering an area of 586,400 square miles and almost 20 degrees of latitude from about 51°N to 71°N, the spatial coverage of Alaska is quite expansive. Given the high latitude environment, the state experiences extreme seasonal variability in solar radiation. North of the Arctic Circle, areas experience constant daylight in the summer (often termed the Midnight Sun), but remain in darkness for much of the winter months.
With approximately 6,640 miles of coastline, a significant portion of Alaska is influenced by ocean waters and the seasonal distribution of sea ice. Locations that are under the predominant influence of the sea are characterized by relatively small seasonal temperature variability with high humidity. Conversely, locations that are inland and cut off from the moderating influence of the waters experience a continental climate. This type of climate is characterized by large daily and annual temperature range, low humidity and relatively light and irregular precipitation.
The altitude above sea level influences the climate of a given area. Lower elevations in interior Alaska, such as the Yukon Flats and the Tanana Valley experience extreme cold in the winter as well as high summertime temperatures. Additionally, temperature inversions are frequent in winter, in which the lower atmosphere is essentially decoupled from the upper levels. This generally occurs under clear skies, winds are light, and surface temperatures are extremely low. However, locations only a few hundred feet above the surface can be significantly warmer. In other parts of the state, such as the southern coast, locations at high elevations receive much higher precipitation and temperatures are generally cooler.