morning cold; morning chill
Refers to the coldness felt in the morning, especially in autumn or winter. Often used in poetic or descriptive contexts. Compare with 夜寒 (よさむ, 'night cold').
See also: 夜寒
The morning cold has become severe, so I turned on the heater.
I like going for a walk in the morning chill.
Compound of 朝 (あさ, 'morning') and 寒 (さむ, 'cold'). The reading さむ is the noun form of the adjective 寒い (さむい).