Nordenskjöld line

Nordenskjöld line

[′nȯrd·ən‚shēld ‚līn]
(climatology)
The line connecting all places at which the mean temperature of the warmest month is equal (in degrees Celsius) to 9 - 0.1 k, where k is the mean temperature of the coldest month (in degrees Fahrenheit it becomes 51.4 - 0.1 k).