Sun Path & Solar Angles for Washington, DC

Direct answer

Calculated solar-noon angles and a first-pass fixed-shading worksheet for Washington, DC, using transparent solar geometry rather than an unexplained chart. A key reference is latitude: 38.9072° N; check the cited source, edition, units, and applicability before using it for design, compliance, procurement, or approval. Latitude is 38.9072° N; Washington, DC. June solstice noon is 74.5°; south at solar noon. Equinox noon is 51.1°; geometric solar noon. Projection ratio = 1 / tan(solar altitude). Multiply the ratio by the vertical distance the noon shadow must cover. Use this only as a hand check before a full-year study. Read the values with the cited source, edition or observation period, units and applicability; replace illustrative inputs with current project evidence before design, procurement or approval use.

Content and cited inputs reviewed by Scott Barrington, Harth founder and architectural technology specialist · Published 2026-08-17 · Updated 2026-08-17.

Which solar conditions control the result?

Projection ratio = 1 / tan(solar altitude). Multiply the ratio by the vertical distance the noon shadow must cover. Use this only as a hand check before a full-year study.

Washington, DC shading record

Record facade azimuth, window head and sill, overhang height, required shaded dates and hours, coordinates (38.9072° N), time zone (America/New_York), calculation method, surrounding obstructions, reviewer and date. Compare the full model against the three noon ratios above and retain screenshots of the critical summer and shoulder-season hours. Verify hourly positions with the NOAA Solar Calculator.

Where can you explore related guidance?

• Explore all solar data guidance
• Understanding Sun-Path Diagrams
• Solar Altitude and Azimuth Explained
• Climate Design Data Workflow for Washington, DC

Sources and method

Original calculation using latitude 38.9072° N and declinations +23.44°, 0°, and -23.44°. Formula: altitude = 90° - |latitude - declination|. Time zone: America/New_York. Verify occupied-hour positions with the NOAA Solar Calculator; values omit refraction, equation of time, terrain, obstructions, and facade azimuth.

Source links

• gml.noaa.gov