Climatological Data - The Interior Basin
The Interior region of Alaska has a continental climate with the warmest summers in the state, as well as the lowest record winter temperatures. Mean annual temperatures average slightly below freezing, with individual years at some stations above freezing. In general, the Interior ecosystem is spruce-dominated: black spruce and spaghnum moss on poorly drained permafrost with a thin active layer (muskeg) and white spruce on the better drained uplands. Permafrost is discontinuous and easily disturbed by fire or human activity. The tree line is on the order of 300ft elevation or lower, sloping downward toward the west and north.
Climate Data

Region -
Temperature and Precipitation
Location -
This region is bounded by the watersheds of the Brooks Range to the north and the Alaska Range to the south. There are no long-term stations above tree line, however, and the climate actually observed is that of the valleys, especially the broad valleys of the Yukon, Tanana and Kuskokwim Rivers. Wintertime temperatures are strongly controlled by ground-based inversions, and as such may vary widely over short distances and in response to human modification of the local environment.
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About the products: Means are based on daily observations over the period 1971 - 2000, the most recent climatological normal period. The period of record for extremes varies by station.