clear winter skies; clear winter weather
Refers to fine, sunny weather during the winter season, often implying crisp, clear air.
Today is a clear winter day, and Mt. Fuji is clearly visible.
冬晴れの日は空気が澄んで気持ちがいい。
On clear winter days, the air is crisp and it feels refreshing.
Compound of 冬 (ふゆ, winter) and 晴れ (はれ, clear weather). The reading ふゆばれ follows standard rendaku voicing.