IPA: /ˈwɔːrn.nəs/
KK: /wɔrmnəs/
The state of having a comfortable or moderate heat.
The warmness of the sun made the day feel pleasant.
Warmness → It is formed from "warm" (from Old English *wearm*, meaning having a moderate degree of heat) and "-ness" (meaning the state or quality of). The word "warmness" refers to the state of being warm or having warmth.
Think of the word 'warm' which describes a moderate heat, and remember that 'warmness' means the quality of being warm.