Sun Path: London, UK

Direct answer

For London at 51.5085, -0.1257, the declination-only solar-noon altitude is approximately 61.9° at the June solstice, 38.5° at an equinox and 15.1° 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 2643743 in administrative area ENG, at 51.5085, -0.1257; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 61.9° at the June solstice, 38.5° at an equinox and 15.1° at the December solstice. Representative 21st-day geometry ranges from about 7.6 hours in December to 16.4 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.

Content and cited inputs reviewed by Harth team · Published 2026-08-26 · Updated 2026-08-31.

What must be verified for London?

London is represented here at approximately 51.5085, -0.1257 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 London site remain authoritative.

Which related searches does this primary location record cover?

This primary route consolidates the location evidence needed for Sun Path, Solar Altitude & Azimuth, Solar Shading Design, Daylight & Orientation. A narrower route should be released only when it adds a materially different official source, calculation, process, threshold or worked example.

London monthly solar geometry check for sun path

London solar-geometry fingerprint at 51.5085, -0.1257

• London, 21 January: declination -20.14°, noon altitude 18.35°, zenith 71.65°, geometric daylight 8.339 hours, and vertical-object noon shadow ratio 3.014.
• London, 21 February: declination -11.23°, noon altitude 27.27°, zenith 62.73°, geometric daylight 10.073 hours, and vertical-object noon shadow ratio 1.940.
• London, 21 March: declination -0.40°, noon altitude 38.09°, zenith 51.91°, geometric daylight 11.932 hours, and vertical-object noon shadow ratio 1.276.
• London, 21 April: declination +11.58°, noon altitude 50.07°, zenith 39.93°, geometric daylight 13.991 hours, and vertical-object noon shadow ratio 0.837.
• London, 21 May: declination +20.14°, noon altitude 58.63°, zenith 31.37°, geometric daylight 15.661 hours, and vertical-object noon shadow ratio 0.610.
• London, 21 June: declination +23.45°, noon altitude 61.94°, zenith 28.06°, geometric daylight 16.408 hours, and vertical-object noon shadow ratio 0.533.
• London, 21 July: declination +20.44°, noon altitude 58.93°, zenith 31.07°, geometric daylight 15.727 hours, and vertical-object noon shadow ratio 0.602.
• London, 21 August: declination +11.75°, noon altitude 50.25°, zenith 39.75°, geometric daylight 14.023 hours, and vertical-object noon shadow ratio 0.832.
• London, 21 September: declination -0.20°, noon altitude 38.29°, zenith 51.71°, geometric daylight 11.966 hours, and vertical-object noon shadow ratio 1.267.
• London, 21 October: declination -11.75°, noon altitude 26.74°, zenith 63.26°, geometric daylight 9.977 hours, and vertical-object noon shadow ratio 1.985.
• London, 21 November: declination -20.44°, noon altitude 18.05°, zenith 71.95°, geometric daylight 8.273 hours, and vertical-object noon shadow ratio 3.069.
• London, 21 December: declination -23.45°, noon altitude 15.04°, zenith 74.96°, geometric daylight 7.592 hours, and vertical-object noon shadow ratio 3.721.

Harth computed the London fingerprint for latitude 51.5085° with the Cooper declination approximation, 90° - |latitude - declination| at solar noon, centre-to-centre sunrise hour angle and 1 / tan(altitude) shadow ratio. Longitude -0.1257° 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: Luton, UK
• Sun Path: Southend-on-Sea, UK
• Sun Path: Reading, UK
• All solar & daylight data guidance for United Kingdom
• Climate Design Data: London, UK
• House Construction Cost Planning: London, United Kingdom
• Office Construction Cost Planning: London, United Kingdom
• Retail Construction Cost Planning: London, United Kingdom

Sources and method

Location data from the GeoNames GB dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 2643743). Regulatory starting point: UK and devolved building-control authorities. 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.uk

• gml.noaa.gov