Why do the nights seem brighter in winter?

relative humidity percentage of full saturation. absolute humidity volume of water per volume of air. latter proportional temperature: colder less moisture air can contain , sky looks brighter.

if live @ mid-latitudes once under cold , dry polar air, under temperate moist air, on each side of polar front, can know looking outside in morning , judging visibility.

each morning, window of bedroom, looking in direction can see, or not see surrounding hills. tells me kind of air masses subject to.

or me?

Science & Mathematics Weather Next