“What is a Season?”. www.twinkl.ar. 2025年2月9日閲覧。 “Season
Discover how and why we experience changing seasons, and how to help children understand, too. Learn about how nature - weather, animals and trees - signal seasonal transitions.”
Lerner, K. Lee; Lerner, Brenda Wilmoth (2003). World of earth science. Farmington Hills, MI: Thomson-Gale. p. 487. ISBN0-7876-9332-4. OCLC60695883. "Although these distances seem counterintuitive to residents of the Northern Hemisphere who experience summer in July and winter in January — the seasons are not nearly as greatly affected by distance as they are by changes in solar illumination caused by the fact that Earth’s polar axis is inclined 23.5 degrees from the perpendicular to the ecliptic (the plane of the solar system through or near which most of the planet’s orbits travel) and because the Earth exhibits parallelism (currently toward Polaris, the North Star) as it revolves about the Sun."
