Sun Path: Douglas, Ireland

Direct answer

For Douglas at 51.8744, -8.4350, the declination-only solar-noon altitude is approximately 61.6° at the June solstice, 38.1° at an equinox and 14.7° at the December solstice. Refine these geometry checks with the project date, civil time, facade azimuth, terrain and local horizon. The reproducible location record is GeoNames ID 2964690 in administrative area M, at 51.8744, -8.4350; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 61.6° at the June solstice, 38.1° at an equinox and 14.7° at the December solstice. Representative 21st-day geometry ranges from about 7.5 hours in December to 16.5 hours in June; this excludes atmospheric refraction, terrain and obstruction effects. The cited national authority is a discovery starting point; current local documents and a named qualified reviewer control project use of this sun path record.

Prepared by Harth · Prepared from the cited location and country sources; local project inputs remain unreviewed · Published 2026-08-26 · Updated 2026-08-31.

What must be verified for Douglas?

Douglas is represented here at approximately 51.8744, -8.4350 for discovery and workflow planning. A project address, parcel, elevation, exposure, authority, and submission date must replace that city-centre reference before design use.

How should sun path be established?

1. Fix the surveyed site and local time basis.
2. Select an authoritative weather source or a named solar-position algorithm.
3. Record period, percentile or scenario and units.
4. Test sensitivity to elevation, exposure, urban form and horizon.
5. Save the source file, retrieval date and checker in the model record.

What are the limits of this worksheet?

This sun-path-workflow page is a project-starting worksheet, not a design value or approval. The controlling authority and qualified professionals for the Douglas site remain authoritative.

Douglas monthly solar geometry check for sun path

Douglas solar-geometry fingerprint at 51.8744, -8.4350

• Douglas, 21 January: declination -20.14°, noon altitude 17.99°, zenith 72.01°, geometric daylight 8.286 hours, and vertical-object noon shadow ratio 3.080.
• Douglas, 21 February: declination -11.23°, noon altitude 26.90°, zenith 63.10°, geometric daylight 10.047 hours, and vertical-object noon shadow ratio 1.971.
• Douglas, 21 March: declination -0.40°, noon altitude 37.72°, zenith 52.28°, geometric daylight 11.931 hours, and vertical-object noon shadow ratio 1.293.
• Douglas, 21 April: declination +11.58°, noon altitude 49.70°, zenith 40.30°, geometric daylight 14.018 hours, and vertical-object noon shadow ratio 0.848.
• Douglas, 21 May: declination +20.14°, noon altitude 58.26°, zenith 31.74°, geometric daylight 15.714 hours, and vertical-object noon shadow ratio 0.618.
• Douglas, 21 June: declination +23.45°, noon altitude 61.58°, zenith 28.42°, geometric daylight 16.474 hours, and vertical-object noon shadow ratio 0.541.
• Douglas, 21 July: declination +20.44°, noon altitude 58.57°, zenith 31.43°, geometric daylight 15.780 hours, and vertical-object noon shadow ratio 0.611.
• Douglas, 21 August: declination +11.75°, noon altitude 49.88°, zenith 40.12°, geometric daylight 14.050 hours, and vertical-object noon shadow ratio 0.843.
• Douglas, 21 September: declination -0.20°, noon altitude 37.92°, zenith 52.08°, geometric daylight 11.966 hours, and vertical-object noon shadow ratio 1.283.
• Douglas, 21 October: declination -11.75°, noon altitude 26.37°, zenith 63.63°, geometric daylight 9.950 hours, and vertical-object noon shadow ratio 2.017.
• Douglas, 21 November: declination -20.44°, noon altitude 17.68°, zenith 72.32°, geometric daylight 8.220 hours, and vertical-object noon shadow ratio 3.136.
• Douglas, 21 December: declination -23.45°, noon altitude 14.68°, zenith 75.32°, geometric daylight 7.526 hours, and vertical-object noon shadow ratio 3.818.

Harth computed the Douglas fingerprint for latitude 51.8744° with the Cooper declination approximation, 90° - |latitude - declination| at solar noon, centre-to-centre sunrise hour angle and 1 / tan(altitude) shadow ratio. Longitude -8.4350° is retained for a later civil-time conversion; this screen does not perform that conversion. See NOAA's solar calculation details. Atmospheric refraction, terrain, facade azimuth and obstructions remain outside this first-pass comparison.

Where can you explore related guidance?

• Explore all solar data guidance
• Sun Path: Cork, Ireland
• Sun Path: Carrigaline, Ireland
• Sun Path: Ballincollig, Ireland
• Sun Path: Castletroy, Ireland
• All solar & daylight data guidance for Ireland
• Climate Design Data: Douglas, Ireland

Sources and method

Location data from the GeoNames IE dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 2964690). Regulatory starting point: Department of Housing, Local Government and Heritage and the local building-control authority. Figures are illustrative — verify against the current locally adopted edition for the site. Solar-method context: NOAA Solar Calculation Details; the Harth monthly table uses a simpler declination and geometric-daylight approximation whose stated limitations must be retained.

Source links

• download.geonames.org

• gov.ie

• gml.noaa.gov