The Dog Days of summer start next weekend

The term “dog days of summer” came up today and Maria asked why the period is so named.

I didn’t know, but quickly found this explanation online.

The brightest star in the night sky is Sirius, named the “Dog Star” because it is in the constellation Canis Major (bigger dog). The Romans believed it was so bright that it gave heat to the earth. Sirius can be seen easily in the winter sky, but it rises and sets with the sun in the summer. Sirius is in conjunction with the sun in late July and the Romans believed its heat, added to that of the sun, made for a period of hot, sultry weather. They called the period from 20 days before the conjunction to 20 days after it “dog days” after the Dog Star.

The gradual drifting of earth’s relationship to the constellations over the centuries has advanced the period so it runs from July 3 to August 11.

So now you know.