October runs 31 days, and like September, its name preserves a number from an older Roman calendar — “octo” means eight, since October was originally the eighth month before January and February were added to the start of the year.
In the Northern Hemisphere, October is a hallmark autumn month: temperatures continue to drop, deciduous trees put on their most vivid color displays, and daylight keeps shrinking toward the winter months ahead. In the Southern Hemisphere, October sits in mid-spring, with warming temperatures and lengthening days as summer approaches.
October is widely known for Halloween on October 31st, observed in many countries with costumes, trick-or-treating, and imagery centered on the autumn harvest and the approach of darker, colder months. It’s also a popular month for harvest festivals and celebrations tied to the changing season in the Northern Hemisphere. With 31 days, October is one of the seven “long” months in the calendar.