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

See Examples For:

dog days

In the dog days of summer, there’s no better place to escape the heat than inside the air-conditioned paradise of a movie theater.

From Salon ● Aug. 15, 2026

The only one I’m aware of is that August comes during the so-called dog days of summer, when trading volume is relatively light.

From MarketWatch ● Jul. 23, 2026

The same as the dog days under Russell Martin, the same as the demise under Philippe Clement, the same as the downfall in the Michael Beale months.

From BBC ● Oct. 23, 2025

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

From Slate ● Jul. 26, 2025

The Dodgers were 7½ games ahead of the second-place Cardinals when the dog days of August ended.

From "In the Year of the Boar and Jackie Robinson" by Bette Bao Lord