For some in the U.S. where the temperatures have been scorching hot, it might be hard to believe that tomorrow is just the first day of Summer! In the Northern Hemisphere, the start date of summer is based on the summer solstice, when the sun is in the most northern point from the Earth’s equator. This will also be the longest day of the year, delivering on average 14.5 hours of sunshine! From today forward though, the days will start getting shorter.
Of course, that doesn’t mean the temperatures will necessarily start cooling down. In fact, the 90s and 100s many of us just endured – and in some cases continue to endure – were delivered by Spring, which has me kind of dreading what “The Dog Days of Summer” might have in store!
The Farmer’s Almanac more specifically puts the “Dog Days” as the 40-days between July 3 and August 11. Now of course we have to ask, how did “Dog Days” come to describe the hottest part of Summer? This actually goes back to Ancient Rome and derives from the star Sirius, aka “the dog star.” It’s part of the constellation Canis Major, which means Large Dog, and is the brightest star in the night sky. We know now that Sirius is actually a star system, but is seen by the naked eye as a single star. Toward the beginning of the Roman Summer, Sirius would disappear from the night sky and start rising and setting in conjunction with the Sun. The Roman’s believed that the “heat” from Sirius added to the heat of the Sun during this time, creating a string of steamy hot “Dog Days.”
Interestingly, Sirius no longer rises at the same time as the Sun because of what’s known as “axial precession”. Very simply explained, the angle the Earth sits on its axis changes over time, thus altering when and where the stars appear for us as compared to thousands of years ago. It takes about 26,000 years for Earth’s axis of rotation to complete a full circle!
The “Dog Days” have always had some interesting folklore behind them as well. Many ancient cultures believed them to be a time of evil. The Greeks thought that Sirius caused abnormal behavior in animals and men. The poor souls suffering from the star’s emanations were said to be “Star-Struck.” Romans actually sacrificed dogs and sheep to the goddess Robigo in order to prevent the stars emanations from causing wheat rust. The Ancient Egyptians believed Sirius caused the annual flooding of the Nile, which was actually a celebrated occurrence. There are quite a few funny old wives tales about “Dog Days” that I remember from when I was a kid… and one that I still hear to this day is that if it is dry on the first day, July 3rd, it will stay abnormally dry for the next 40 days. The agricultural commodity markets will be watching closely!