• NSIDC's website will undergo planned maintenance on Wednesday, January 15, from 10 a.m. to 12 p.m. (U.S. Mountain Time). During this time, the NSIDC.org website and most NSIDC data access may be briefly unavailable.

air thawing index
the cumulative number of degree-days above 0°C for the air temperature during a given period.
Topic(s):
climatology and meteorology
frozen ground or permafrost