Solar & Daylight Data

Updated 2026-08-31

Sun Path: Mthatha, South Africa

How to research sun path for a specific site in Mthatha — 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 ZA dump](https://download.geonames.org/export/dump/ZA.zip) (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 946058). Regulatory starting point: [South African Bureau of Standards and the local authority](https://www.sabs.co.za/). 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 Mthatha at -31.5889, 28.7844, the declination-only solar-noon altitude is approximately 35.0° at the June solstice, 58.4° at an equinox and 81.8° 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 946058 in administrative area 05, at -31.5889, 28.7844; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 35.0° at the June solstice, 58.4° at an equinox and 81.8° at the December solstice. Representative 21st-day geometry ranges from about 9.9 hours in June to 14.1 hours in December; 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 Mthatha?

Mthatha is represented here at approximately -31.5889, 28.7844 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 Mthatha site remain authoritative.

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.

Mthatha monthly solar geometry check for sun path

Representative dateDeclinationSolar-noon altitudeGeometric daylight
21 January-20.14°78.5°13.7 h
21 February-11.23°69.6°12.9 h
21 March-0.40°58.8°12.0 h
21 April+11.58°46.8°11.0 h
21 May+20.14°38.3°10.3 h
21 June+23.45°35.0°9.9 h
21 July+20.44°38.0°10.2 h
21 August+11.75°46.7°11.0 h
21 September-0.20°58.6°12.0 h
21 October-11.75°70.2°13.0 h
21 November-20.44°78.9°13.8 h
21 December-23.45°81.9°14.1 h

Month-by-month geometry interpretation

  • 21 January: approximate solar-noon altitude 78.5° (zenith angle 11.5°) and 13.7 hours of geometric daylight. That is 0.3 hours shorter than the preceding representative date in this annual sequence.
  • 21 February: approximate solar-noon altitude 69.6° (zenith angle 20.4°) and 12.9 hours of geometric daylight. That is 0.8 hours shorter than the preceding representative date in this annual sequence.
  • 21 March: approximate solar-noon altitude 58.8° (zenith angle 31.2°) and 12.0 hours of geometric daylight. That is 0.9 hours shorter than the preceding representative date in this annual sequence.
  • 21 April: approximate solar-noon altitude 46.8° (zenith angle 43.2°) and 11.0 hours of geometric daylight. That is 1.0 hours shorter than the preceding representative date in this annual sequence.
  • 21 May: approximate solar-noon altitude 38.3° (zenith angle 51.7°) and 10.3 hours of geometric daylight. That is 0.8 hours shorter than the preceding representative date in this annual sequence.
  • 21 June: approximate solar-noon altitude 35.0° (zenith angle 55.0°) and 9.9 hours of geometric daylight. That is 0.3 hours shorter than the preceding representative date in this annual sequence.
  • 21 July: approximate solar-noon altitude 38.0° (zenith angle 52.0°) and 10.2 hours of geometric daylight. That is 0.3 hours longer than the preceding representative date in this annual sequence.
  • 21 August: approximate solar-noon altitude 46.7° (zenith angle 43.3°) and 11.0 hours of geometric daylight. That is 0.8 hours longer than the preceding representative date in this annual sequence.
  • 21 September: approximate solar-noon altitude 58.6° (zenith angle 31.4°) and 12.0 hours of geometric daylight. That is 1.0 hours longer than the preceding representative date in this annual sequence.
  • 21 October: approximate solar-noon altitude 70.2° (zenith angle 19.8°) and 13.0 hours of geometric daylight. That is 1.0 hours longer than the preceding representative date in this annual sequence.
  • 21 November: approximate solar-noon altitude 78.9° (zenith angle 11.1°) and 13.8 hours of geometric daylight. That is 0.8 hours longer than the preceding representative date in this annual sequence.
  • 21 December: approximate solar-noon altitude 81.9° (zenith angle 8.1°) and 14.1 hours of geometric daylight. That is 0.3 hours longer than the preceding representative date in this annual sequence.

Harth calculation for latitude -31.5889°: Cooper declination approximation, 90° - |latitude - declination| at solar noon, and centre-to-centre sunrise hour angle. See NOAA's solar calculation details for fuller method context. This screening table excludes equation-of-time/civil-time conversion, atmospheric refraction, terrain, facade azimuth and obstructions; it is not an hourly shading result.

Sources and method

Location data from the GeoNames ZA dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 946058). Regulatory starting point: South African Bureau of Standards and the local 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.

Frequently asked questions

What does the sun path record for Mthatha establish?

The sun path record for Mthatha establishes a reproducible discovery point at -31.5889, 28.7844 (GeoNames ID 946058, administrative area 05) and a South Africa 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 Mthatha?

For the sun path record in Mthatha, replace the -31.5889, 28.7844 city reference with the surveyed site or parcel, identify the competent local authority, and verify the current documents under National Building Regulations and SANS 10400, as applied by the local authority. Record the edition, retrieval date, units, assumptions and named checker before relying on the result.

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