The Dog Days of Summer

August has arrived and the ‘dog days of summer’ are settling in across Cambridge, as the rising heat and humidity remind us all of Cambridgeshire’s true identity as a fen.


The term ‘dog days’ arrived in the English language through a translation of caniculares dies, or the days surrounding the heliacal (sunrise) rising of the Dog Star, Sirius. It was a standard classical description of a time of year associated with extreme heat, lethargy, and illness. In the Iliad, Book XXII, Homer writes that, as Achilles approached Troy, ‘Old Priam was the first to see him, racing over the plain, his bronze breastplate gleaming like Sirius, the star of harvest, brightest of stars in the dark of night. Orion’s Dog, men call it, glittering brightly yet boding ill, bringing fever to wretched mortals’. CCCC MS 81, a paper manuscript of the mid-fifteenth century, contains Homer’s Iliad and Odyssey and, Quintus of Smyrna’s Posthomerica.

To see how the term reached English, we can look at The Red Book of Darley, the second part of CCCC MS 422. It is an English Missal manuscript, probably from the church of St Helen, Darley Dale, in the Lake District. Its Easter table suggest that it was written in the 1060s, probably circa 1061, and it is composed in a combination of Latin and Old English.

MS 422, p. 35
MS 422, p. 35

The table for July, on page 35, gives the description of the 13th of the month as, ‘Sce Myldriðe, dies caniculares’ with a gloss of ‘hare dagas’. This means it was the day of Saint Mildreth and the beginning of the dies caniculares, the hare dagas, alternately written as háradagas, which were the dog days. The etymology of this term is from the Anglo-Saxon word for the Dog Star, hárasteorra. The literal translation of the Old English would be Hoary Star, or perhaps Grey Star. This is an interesting example of translating sense for sense, not word for word- the glosser was most interested in identifying the ‘dies caniculares’ as an astronomical event, which was best represented by using the native term for the star in question.

The historiated initial of CCCC MS 75, f. 180v, depicts the shepherds seeing the star to herald Jesus' birth, and their small dog.
The historiated initial of CCCC MS 75, f. 180v, depicts the shepherds seeing the star to herald Jesus’ birth, and their small dog.

Translating caniculares dies into dog days seems to begin sometime in the early Renaissance period. John Trevisa writes, in 1398 ‘in the mydle of the monthe Iulius the Canicular dayes begyn,’  Lydgate uses the term ‘canyculeres‘ in 1430, and, in 1538, Thomas Elyot defines ‘Canicula…a sterre, wherof canicular or dogge days be named Dies caniculares.’

So why did ‘dog days’ win out to describe the tail end of summer and not just the loan word canicular ? Is it the imagery of the term- a panting dog drooping in the heat? Or perhaps it is its connection to our other phrases and words using the same root, like ‘dog-tired’ or ‘dogged’? Or maybe it is simply the alliteration and rhythm of the phrase, which would please the Anglo-Saxon poetic sense as well.

In any case, all we can do is wait for those first cool days of Autumn, and know that man’s best friend was only dragged into this muggy time of year through the naming of a star.

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