A graphical map of where the sun sits in the sky over a location across the day and year. A stereographic (polar) version looks down on the sky dome: compass direction runs around the circle, altitude from horizon at the edge to overhead at the center, with curved lines tracing the sun's path on key dates and radial lines marking the hours.
To orient buildings, size overhangs and shading, place glazing and outdoor rooms, plan daylighting and passive solar strategies, study shadows on neighbors, and position photovoltaics. Reading summer versus winter sun altitude is what lets a south overhang shade July while admitting December sun.
The sun's noon altitude equals 90° minus your latitude plus the sun's declination for that day (−23.44° at winter solstice, +23.44° at summer). Nearer the equator the sun climbs higher and paths flatten toward overhead; nearer the poles it stays lower and paths compress toward the horizon.
It uses standard solar-geometry equations (NOAA-style declination and hour-angle formulas) and is accurate to within a fraction of a degree for design purposes. Times are shown in solar time; convert to clock time by adjusting for your longitude within the time zone, the equation of time and daylight saving.
Solar noon is when the sun crosses due south (in the northern hemisphere), which rarely matches 12:00 on a clock. The gap comes from your position within the time zone, the equation of time (up to about 16 minutes), and daylight saving. This diagram plots solar time so the geometry stays exact.