dead of

1. The period of greatest intensity of something, such as darkness or cold. For example, I love looking at seed catalogs in the dead of winter, when it's below zero outside. The earliest recorded use of dead of night, for “darkest time of night,” was in Edward Hall's Chronicle of 1548: “In the dead of the night ... he broke up his camp and fled.” Dead of winter, for the coldest part of winter, dates from the early 1600s.

Example Sentences

Then came a flash of light so bright that in the dead of night they could briefly see out their window the rocks and gullies of the San Gabriel foothills behind their house.

From Los Angeles Times

In fact, seemingly everyone in Northland heard immediately about the glamorous French yachtsmen taking a holiday cruise in the dead of winter.

From Slate

But some Ukrainians are waging a secret resistance against Russia, and in the dead of the night, they spray paint Ukrainian blue and yellow colours on walls, and also paste leaflets with messages like "Liberate Mariupol" and "Mariupol is Ukraine".

From BBC

By the next day he was warning the roughly 10 million residents of Tehran, Iran's capital, to flee in the dead of night.

From Salon

When they broke into a Brink’s big rig at a remote Grapevine truck stop in the dead of night three years ago, the men may have gotten more than they bargained for: a haul that could be worth up to $100 million.

From Los Angeles Times