Model scope and corrections — read first
Azimuth A is measured clockwise from true north: N 0°, E 90°, S 180°, W 270°. For solar altitude h, observer latitude φ, and declination δ, the general relation is cos A = (sin δ − sin φ·sin h)/(cos φ·cos h). At geometric sunrise (h = 0°), this simplifies to cos A_rise = sin δ / cos φ, provided sunrise exists and the denominator is nonzero. A_rise should not label the general expression at arbitrary h. During polar day or night, the solar path may not cross the horizon, so sunrise and sunset azimuths are undefined. Due-east sunrise at an equinox is an ideal approximation with polar exceptions and atmospheric-refraction effects.
Geographic Time · Module 05
SunApparent motion
Celestial dome · Sunrise and sunset directions · Noon altitude · Polar-day paths
Observer latitude φ (counterintuitive exploration)