isocrymal

Century Dictionary and Cyclopedia

1. n. A line, imaginary or drawn upon a map or chart of any region, connecting points at which the temperature is the same during some specified coldest portion of the year. The word was introduced by J. D. Dana, and used by him with reference to the mean temperature of the ocean surface “for the coldest thirty consecutive days of the year.”
2. n. In hydrogeology, a line joining places where the mean minimum temperatures of the ocean water are the same.
3. Having equal degrees of cold or equal low temperatures at any time or under any condition; having equal freezing temperatures.
4. Having similar physical properties at specific low temperatures.

Wiktionary

1. adj. Relating to isocrymes.

GNU Webster's 1913

1. adj. (Phys. Geog.) Pertaining to, having the nature of, or illustrating, an isocryme