dog days

American  

plural noun

1. the sultry part of the summer, supposed to occur during the period that Sirius, the Dog Star, rises at the same time as the sun: now often reckoned from July 3 to August 11.

2. a period marked by lethargy, inactivity, or indolence.

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dog days British  

plural noun

1. the hot period of the summer reckoned in ancient times from the heliacal rising of Sirius (the Dog Star)

2. a period marked by inactivity

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dog days Cultural  

1. The hot, muggy days of summer. The Romans associated such weather with the influence of Sirius, the dog star, which is high in the sky during summer days.

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dog days Idioms  

1. Hot, sultry summer weather; also, a period of stagnation. For example, It's hard to get much work done during the dog days, or Every winter there's a week or two of dog days when sales drop dramatically. The term alludes to the period between early July and early September, when Sirius, the so-called Dog Star, rises and sets with the sun. The ancient Romans called this phenomenon dies caniculares, which was translated as “dog days” in the first half of the 1500s.

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Other Word Forms

• dog-day
  adjective

Etymology

Origin of dog days

1530–40; translation of Latin diēs caniculārēs; see canicular

Example Sentences

At least as I perceive it, there’s a strange coldness that wasn’t here before, ironic given how hot it is in the dog days of summer.

From Salon • Dec. 18, 2025

Felix, Emily, and Elizabeth disclose what they’re reading during the dog days of summer.

From Slate • Jul. 26, 2025

A suggested title for any upcoming films, books or TV series that are set in the dog days of 2025?

From Los Angeles Times • Jul. 22, 2025

The sanfu season, known to be China's "dog days", usually starts in mid-July.

From BBC • Jul. 9, 2025

These are strange and breathless days, the dog days, when people are led to do things they are sure to be sorry for after.

From "Tuck Everlasting" by Natalie Babbit