canicular (adj.)

late 14c., in caniculer dayes, the "dog days" around mid-August, from Latin canicularis "pertaining to the dog days or the Dog Star," from canicula "little dog," also "the Dog Star," diminutive of canis "a dog" (from PIE root *kwon- "dog"). In literal use ("pertaining to a dog") historically only as attempt at humor.

Also see Sirius, and compare heliacal. The ancient Egyptian canicular year was computed from the heliacal rising of Sirius; the canicular cycle of 1,461 years is how long it would take a given day to pass through all seasons in an uncorrected calendar.