Northern Hemisphere Seasons -

Summer starts at the Summer Solstice (~June 20/21)—the longest day of the year. Above the Arctic Circle, the sun does not set (midnight sun). The hemisphere leans maximally toward the sun.

| Feature | Spring | Summer | Autumn | Winter | |--------|--------|--------|--------|--------| | | Increasing | Max (longest day) | Decreasing | Min (shortest day) | | Temp trend | Warming | Peak heat | Cooling | Extreme cold | | Key weather | Showers, thaw | Heatwaves, storms | Windy, frost | Snow, ice, blizzards | | Vegetation | Blooming, green | Full growth | Senescence, color | Dormant, bare | | Animal activity | Births, return | Breeding, feeding | Migration, storage | Hibernation, survival | | Human mood | Hopeful, energetic | Social, active | Reflective, busy | Cozy, introspective | northern hemisphere seasons

The seasons in the Northern Hemisphere are the opposite of those in the Southern Hemisphere. When it is Summer in the north, it is Winter in the south. Summer starts at the Summer Solstice (~June 20/21)—the

Astronomical Alignment Overview [June Solstice] ---------> North Pole tilts TOWARD Sun (Summer) ^ | [March Equinox] ---------> Sun directly over Equator (Spring) ^ | [December Solstice] -------> North Pole tilts AWAY from Sun (Winter) ^ | [Sept. Equinox] ---------> Sun directly over Equator (Autumn) | Feature | Spring | Summer | Autumn

The primary driver of the seasons is the . The Earth rotates on an axis that is tilted at an angle of approximately 23.5 degrees relative to its orbital plane.

Understanding how these seasons operate requires examining the astronomical alignments that initiate them, the meteorological frameworks used to track them, and the profound effects they have on global ecosystems and human societies. The Astronomical Mechanism Behind the Seasons