Etomology of Dog Days

Here is an NPR: All Things Considered podcast on the origin of  the phrase Dog Days with writer Jon Katz.  



 1530s, from Latin dies caniculares, from Ancient Roman
In 3000 B.C., Ancient Egypt it coincided with the summer solstice, which also was the new year and the beginning inundation of the Nile. A dog association began here (the star's hieroglyph was a dog) but the reasons for it are obscure.

Romans referred to the dog days as diēs caniculārēs and associated the hot weather with the star Sirius was called Dog Star because it is the brightest star in the constellation Canis Major (Large Dog). Sirius is also the brightest star in the night sky.


Romans sacrificed a red dog in April to appease the rage of Sirius, believing that the star was the cause of the hot, sultry weather.

Meaning very hot days during July and August.

Dog Days were popularly believed to be an evil time "the Sea boiled, the Wine turned sour, Dogs grew mad, and all other creatures became languid; causing to man, among other diseases, burning fevers, hysterics, and phrensies." according to Brady’s Clavis Calendaria, 1813.^[1]

 Some associate it with growth. Some say summer's dog days signify hot sultry days not fit for a dog, while others suggest its the weather in which dogs go mad.Droughts accour, plagues and madness. Escentially, hacic spread out accos the land.

The phrase Dog Days date back to the ancient Romans. The hottest days of the year, July to August coincide with the appearance of Sirius, the Dog Star in the same part of the sky as the Sun. Sirius is the largest and brightest star in the sky. Romans believed the two stars worked in alliance to create these days of great heat upon its people and the land. "The combination," according to  Joe Roe, "Dog Days of Summer Have Celestial Origin," of the brightest luminary of the day (the sun) and the brightest star of night (Sirius) was responsible for the extreme heat that is experienced during the hieght of the summertime. Other effects, according to the ancients, included droughts, plagues and madness." 

And related how his farm animals accepted the heat.Studies the wonders of how animals accluamte to the climant change socially

Celestial origion

The ancient Romans noticed

Sources: 

http://thesaurus.com

http://www.phrases.org
www.npr.org