July 3 - August 11 - Dog Days of Summer
The Dog Days of Summer, also known as Canicular Days, are typically the hottest and most unhealthy days of the year. The traditional timing of Dog Days is the 40 days beginning July 3rd and ending August 11th coinciding with the heliacal (at sunrise) rising of Sirius. Sirius, the Dog Star, is visible with the rising Sun at this time of year. Ancients associated this sky picture with the hot days that coincided with it. Sirius is the brightest star in the constellation Canis Major (Greater Dog).
August 1 - Felix the Cat's Comic Strip Debut
What would become America's Felix Sunday newspaper comic strip debuted in England's Daily Sketch on August 1, 1923. The series ran weekly for twelve episodes, all of them pencilled and inked by Otto Messmer.
Starting Sunday, August 19, 1923, King Features syndicated the twelve Sketch strips in the United States—reinked by studio boss, Pat Sullivan. They were also published in a different order: the first strip syndicated in the USA had been the third strip in the UK series.
The saga doesn't stop there. The only Stateside paper to run Felix from the start was the Boston American, which published Sunday strips five days late. So while King syndicated Felix's debut on August 19, Felix didn't actually appear in an American newspaper until Friday, August 24.
By the end of the year, things had calmed down. King followed up on the twelve Sketch strips with Sundays both penciled and inked by Messmer. And multiple papers were printing the Sunday strip properly by now—that is to say, on Sunday.