University of Alaska Fairbanks | Scenarios Network for Alaska + Arctic Planning

Thanks for checking out this tool! Until our complete launch in summer 2024, this is a public beta, which means that we’re still gathering feedback, testing data outputs and fixing bugs.

Data from this tool should not yet be used for engineering or decision–making purposes because datasets, while robust, have not yet been fully validated. However, “test driving” the tool by exploring layers and extracting data can be useful for project overviews and “ballpark” estimates.

Learn more about what’s in development and how to provide feedback

Thawing Index

The thawing index, or degree days above freezing, is a measure of thawing that occurs during a year. It is also a measure of summer duration and temperatures.

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Latitude

Longtitude

✓ Modeled Historical (1980–2009, ERA Interim)
Projected Mid–Century (2040–2069, NCAR CCSM4, RCP 8.5)

Thawing index

These layers show the historical or projected thawing index across Alaska.

Degree days above 32°F

	0
	1000
	2000
	3000
	4000
	≥ 5000

The thawing index is the annual cumulative degree days (°F) above freezing for each location. These degree days are calculated by taking the number of degrees above 32°F for each day of the year and adding them together into a single value. A higher thawing index means a warmer year for that location.

Areas with thawing indexes much less than their freezing indexes are candidates for at least some permafrost. Areas with small thawing indexes and large freezing indexes tend to have continuous permafrost.

Larger values indicate warmer temperatures. Increases in thawing index over time suggest warmer and longer summers, increased active layer depth, and a decrease in ice and snow.

Access detailed information about the dataset used to calculate the thawing index, including source data downloads.