A line drawn on a weather map or chart linking all points of equal or constant temperature.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "isotherm" in a sentence
"The treeline is generally coincident with the summer JJA 10°C isotherm, although some argue the isotherm is a response to the treeline because of albedo changes, accumulation of snow and reduced wind speeds."
"The 10C (50F) isotherm, which is cold, is within 500 meters of the 30C (86F) surface."
"There are some who argue that the isotherm is a response to the treeline not as generally assumed."