What does a dog have to do with heat waves?

For the answer, we have to go back a few thousand years in time to ancient Rome. Sirius, the brightest star of the Canis Maior (‘the greater dog’) constellation, first appeared in the sky during summer when the weather was the hottest.

The Romans therefore thought that this constellation (that is the ‘dog’) caused the fierce heat. The diminutive form of the word canis (which means ‘dog’) is canicula (that is ‘small dog’ or ‘puppy’). So during heat waves, it’s one or now many puppies that make the heat. 😊