Sun Path & Solar Angles for Boston, MA
Sun-path design data for Boston, MA: solstice and equinox solar-noon altitude, shadow ratios, assumptions, and an architect-oriented shading worksheet.
Sun Path & Solar Angles for Boston, MA
Direct answer
Calculated solar-noon angles and a first-pass fixed-shading worksheet for Boston, MA, using transparent solar geometry rather than an unexplained chart.
Key facts
| Metric | Value | Notes |
|---|---|---|
| Latitude | 42.3601° N | Boston, MA |
| June solstice noon | 71.1° | south at solar noon |
| Equinox noon | 47.6° | geometric solar noon |
| December solstice noon | 24.2° | geometric solar noon |
Calculated solar-noon geometry
| Date | Declination | Altitude | Projection / vertical shade distance |
|---|---|---|---|
| June solstice | +23.44° | 71.08° | 0.343 |
| Equinox | 0° | 47.64° | 0.912 |
| December solstice | -23.44° | 24.20° | 2.225 |
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.
Boston, MA shading record
Record facade azimuth, window head and sill, overhang height, required shaded dates and hours, coordinates (42.3601° 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 Boston, MA at the summer solstice?
The declination-only solar-noon altitude is approximately 71.1°. 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 42.3601° 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.