midwinter; dead of winter
Refers to the middle or harshest part of winter, often in phrases such as 真冬に and 真冬の寒さ.
真冬にコートなしで外に出るのはつらい。
It is hard to go outside in midwinter without a coat.
I can't believe he swims outdoors in the middle of winter.
Hokkaido is very cold in the dead of winter.
Today is expected to be as cold as midwinter.
冬 refers to the winter season in general, whereas 真冬 narrows it to the coldest, central part of winter.
真冬 is the general, everyday word for 'the depths of winter', while 寒中 is the more technical term tied to the traditional calendar period between 小寒 and 立春.
真夏 means the height of summer, the direct seasonal opposite of 真冬, the height of winter.
day with max temperature below 0°C; cold winter day
A transparent compound of 真, used here as an intensifying prefix meaning 'true' or 'very,' and 冬, 'winter.'