The ancient Romans noted that the brightest star in the night sky -- Sirius -- kept appearing annually at the onset of hot, sultry weather. Somehow Sirius -- which stems from the Greek word for "scorcher" -- became known as the Dog Star, and the weather it heralded was called "dog days." Believing that star caused the miserable weather, the ancient Romans sacrificed brown dogs to appease the rage of Sirius.
Today, we have an abundance of science to explain misnomers like "dog days." We now know that the "aphelion" is an annual inevitability. Every July 3rd, the earth's Northern hemisphere reaches its farthest point from the sun, approximately 94,510,000 miles. That point -- the aphelion -- ironically begins the hottest and stickiest days of the year.