Solar & Daylight Data

Updated 2026-08-31

Sun Path: Wan Chai, Hong Kong

How to research sun path for a specific site in Wan Chai — the controlling authority, source documents, and checks to run before you rely on a number.

Last updated August 31, 2026 · Location data from the [GeoNames HK dump](https://download.geonames.org/export/dump/HK.zip) (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 1818379). Regulatory starting point: [Hong Kong Buildings Department](https://www.bd.gov.hk/en/resources/codes-and-references/codes-and-design-manuals/index.html). Figures are illustrative — verify against the current locally adopted edition for the site. Solar-method context: [NOAA Solar Calculation Details](https://gml.noaa.gov/grad/solcalc/calcdetails.html); the Harth monthly table uses a simpler declination and geometric-daylight approximation whose stated limitations must be retained.

Direct answer

For Wan Chai at 22.2814, 114.1726, the declination-only solar-noon altitude is approximately 88.8° at the June solstice, 67.7° at an equinox and 44.3° 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 1818379 in administrative area HWC, at 22.2814, 114.1726; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 88.8° at the June solstice, 67.7° at an equinox and 44.3° at the December solstice. Representative 21st-day geometry ranges from about 10.6 hours in December to 13.4 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.

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 Wan Chai?

Wan Chai is represented here at approximately 22.2814, 114.1726 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.
InputProject-specific evidenceQA question
Sitesurveyed coordinates, elevation and horizonDoes the point represent the building?
Weather/solar methodnamed dataset, algorithm, period and time basisAre station, time zone and units explicit?
Design scenariocurrent and future scenario agreed by the teamIs an average being mistaken for an extreme?
Complianceadopted local document and editionWas applicability confirmed with the authority?

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 Wan Chai site remain authoritative.

Wan Chai monthly solar geometry check for sun path

Representative dateDeclinationSolar-noon altitudeGeometric daylightNoon shadow / height
21 January-20.14°47.58°10.848 h0.914
21 February-11.23°56.49°11.378 h0.662
21 March-0.40°67.31°11.978 h0.418
21 April+11.58°79.30°12.642 h0.189
21 May+20.14°87.86°13.152 h0.037
21 June+23.45°88.83°13.365 h0.020
21 July+20.44°88.16°13.171 h0.032
21 August+11.75°79.47°12.652 h0.186
21 September-0.20°67.52°11.989 h0.414
21 October-11.75°55.96°11.348 h0.675
21 November-20.44°47.28°10.829 h0.924
21 December-23.45°44.27°10.635 h1.026

Wan Chai solar-geometry fingerprint at 22.2814, 114.1726

  • Wan Chai, 21 January: declination -20.14°, noon altitude 47.58°, zenith 42.42°, geometric daylight 10.848 hours, and vertical-object noon shadow ratio 0.914.
  • Wan Chai, 21 February: declination -11.23°, noon altitude 56.49°, zenith 33.51°, geometric daylight 11.378 hours, and vertical-object noon shadow ratio 0.662.
  • Wan Chai, 21 March: declination -0.40°, noon altitude 67.31°, zenith 22.69°, geometric daylight 11.978 hours, and vertical-object noon shadow ratio 0.418.
  • Wan Chai, 21 April: declination +11.58°, noon altitude 79.30°, zenith 10.70°, geometric daylight 12.642 hours, and vertical-object noon shadow ratio 0.189.
  • Wan Chai, 21 May: declination +20.14°, noon altitude 87.86°, zenith 2.14°, geometric daylight 13.152 hours, and vertical-object noon shadow ratio 0.037.
  • Wan Chai, 21 June: declination +23.45°, noon altitude 88.83°, zenith 1.17°, geometric daylight 13.365 hours, and vertical-object noon shadow ratio 0.020.
  • Wan Chai, 21 July: declination +20.44°, noon altitude 88.16°, zenith 1.84°, geometric daylight 13.171 hours, and vertical-object noon shadow ratio 0.032.
  • Wan Chai, 21 August: declination +11.75°, noon altitude 79.47°, zenith 10.53°, geometric daylight 12.652 hours, and vertical-object noon shadow ratio 0.186.
  • Wan Chai, 21 September: declination -0.20°, noon altitude 67.52°, zenith 22.48°, geometric daylight 11.989 hours, and vertical-object noon shadow ratio 0.414.
  • Wan Chai, 21 October: declination -11.75°, noon altitude 55.96°, zenith 34.04°, geometric daylight 11.348 hours, and vertical-object noon shadow ratio 0.675.
  • Wan Chai, 21 November: declination -20.44°, noon altitude 47.28°, zenith 42.72°, geometric daylight 10.829 hours, and vertical-object noon shadow ratio 0.924.
  • Wan Chai, 21 December: declination -23.45°, noon altitude 44.27°, zenith 45.73°, geometric daylight 10.635 hours, and vertical-object noon shadow ratio 1.026.

Harth computed the Wan Chai fingerprint for latitude 22.2814° with the Cooper declination approximation, 90° - |latitude - declination| at solar noon, centre-to-centre sunrise hour angle and 1 / tan(altitude) shadow ratio. Longitude 114.1726° 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.

Sources and method

Location data from the GeoNames HK dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 1818379). Regulatory starting point: Hong Kong Buildings Department. 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.

Frequently asked questions

What does the sun path record for Wan Chai establish?

The sun path record for Wan Chai establishes a reproducible discovery point at 22.2814, 114.1726 (GeoNames ID 1818379, administrative area HWC) and a Hong Kong source path. It does not establish a final project value, approval or parcel decision.

What must be replaced before using this sun path workflow for a project in Wan Chai?

For the sun path record in Wan Chai, replace the 22.2814, 114.1726 city reference with the surveyed site or parcel, identify the competent local authority, and verify the current documents under Buildings Ordinance, subsidiary regulations, codes of practice, and practice notes. Record the edition, retrieval date, units, assumptions and named checker before relying on the result.

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