Sun Path & Solar Angles for Washington, DC
Sun-path design data for Washington, DC: solstice and equinox solar-noon altitude, shadow ratios, assumptions, and an architect-oriented shading worksheet.
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.
Key facts
| Metric | Value | Notes |
|---|---|---|
| Latitude | 38.9072° N | Washington, DC |
| June solstice noon | 74.5° | south at solar noon |
| Equinox noon | 51.1° | geometric solar noon |
| December solstice noon | 27.7° | geometric solar noon |
Calculated solar-noon geometry
| Date | Declination | Altitude | Projection / vertical shade distance |
|---|---|---|---|
| June solstice | +23.44° | 74.53° | 0.277 |
| Equinox | 0° | 51.09° | 0.807 |
| December solstice | -23.44° | 27.65° | 1.909 |
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.
Frequently asked questions
What is the sun angle in Washington, DC at the summer solstice?
The declination-only solar-noon altitude is approximately 74.5°. This is a transparent geometry check, not a substitute for an hourly solar-position calculation.
Can this size a final overhang?
No. Final shading must test occupied hours, facade azimuth, glass geometry, local horizon, adjacent buildings, terrain, daylight and thermal performance.
Related
Source & 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.