How to Read a Sun Path Diagram: Angles & Time

Solar Path Tracker reports azimuth clockwise from true north. North is 0°, east is 90°, south is 180°, and west is 270°. An azimuth of 72° therefore places the Sun east-north-east, not 72° above the horizon.

Altitude is a separate angle. Zero degrees is the astronomical horizon, positive values are above it, and negative values are below it. A 15° altitude indicates shallow light and usually long shadows; a 70° altitude indicates a high Sun and shorter shadows on level ground.

Read the local-time labels in sequence rather than comparing disconnected points. Before sunrise the altitude is negative. It crosses the horizon near sunrise, rises to a daily maximum around solar noon, then falls through sunset. Clock noon and solar noon are not guaranteed to coincide because longitude, timezone boundaries, and daylight-saving rules affect the displayed clock.

The azimuth curve should be read at the same timestamp as the altitude curve. This pairing tells you both which side of a site faces the Sun and how steeply the direct rays arrive.

Choose the date and hour that match the decision, note azimuth and altitude, then stand or orient a plan toward that bearing. Check whether the real horizon is clear. If an obstacle is present, estimate or measure its angular height and compare it with the solar altitude.

Repeat the observation for a winter and summer date. One day can answer a scheduling question; two seasonal references reveal whether a facade, courtyard, or outdoor workspace behaves differently across the year.