Summer solstice: marks start of summer, longest day. Earth's tilt causes it.
Northern Hemisphere: most daylight, sun's path farthest north.
Southern Hemisphere: winter solstice, shortest day.
Solstices are astronomical; meteorological seasons based on temperature.
Summer: June, July, August, mid-September (Northern Hemisphere).
Equinoxes: equal day-night length, March and September.
Earth's tilted axis changes sun's path, sunrise, sunset positions.
Summer solstice: sun's northernmost point, stable path temporarily.