Summer officially began one week ago today, but our weather has been anything but hot and humid recently. The mercury has not reached 90 degrees at all this month, although there were four straight days with daytime highs well into the 80s from June 7 through 10, including an 89-degree reading June 8.
In case you're wondering, the "dog days" of Summer officially begin this Sunday, July 3, and run through August 11 in the Northern Hemisphere. It all has to do with the star Sirius, known as "the dog star." Sirius is the brightest star in the Northern Hemisphere other than the Sun, and it is found in the constellation Canis Major, thus the name "dog star."
In the Summer, Sirius rises and sets with the Sun. During late July, Sirius is in "conjunction" with the Sun. The ancients believed that its heat added to the heat of the Sun, creating a stretch of hot and sultry weather. They named this period of time, from 20 days before the conjunction to 20 days after, the "dog days," in honor of the dog star.
In ancient times, when the night sky was unobscured by artificial lights and smog, different groups of peoples in different parts of the world drew images in the sky by "connecting the dots" of stars. The images drawn were dependent upon the culture.
The Chinese saw different images than the Native Americans, who saw different pictures than the Europeans. These star pictures are now called constellations, and the constellations that are now mapped out in the sky come from our European ancestors.
They saw images of bears (Ursa Major and Ursa Minor), twins (Gemini), a bull (Taurus), and others, including dogs (Canis Major and Canis Minor). The brightest of the stars in Canis Major (the big dog) is Sirius. The star can be seen prominently in the Winter in the Northern Hemisphere, adjacent to Orion the Hunter.
The conjunction of Sirius with the Sun varies somewhat with latitude. Also, the constellations today are not in exactly the same place in the sky as they were in ancient Rome. The Summer heat is not due to the added radiation from a far-away star, regardless of its brightness. The hot weather is a direct result of the earth's 23.5 degree tilt on its axis, meaning the Northern Hemisphere is tilted toward the Sun during the Summer.
Some showers and a possible thunderstorm are possible later this evening and tonight before much better weather arrives tomorrow through the end of the week. We can expected plenty of sunshine, low humidity, and warm temperatures the next three days. The holiday weekend should be fair, too, with a slight chance of scattered thunderstorms Saturday and Sunday.
Paul
