Merriam-Webster's Word of the Day for July 21, 2026, is "dog days." This plural noun describes the hottest period of summer in the northern hemisphere, typically from early July to early September. The term can also denote a time of stagnation and inactivity, mirroring the lethargy associated with sweltering heat. Such periods make it challenging to muster the energy for demanding tasks. The expression is often associated with finding relief from the summer heat, like by visiting a swimming hole. Historically, "dog days" are linked to the star Sirius, also known as the Dog Star. Sirius represents Orion's hound in the constellation. This star's heliacal rising, coinciding with the sun during summer's peak, historically contributed to the association with sultry weather. This celestial connection explains how dogs became central to the idiom. The phrase captures the feeling of being tempted to avoid work when the weather is oppressively hot.