Sun Path: Whanganui, New Zealand

Direct answer

For Whanganui at -39.9333, 175.0500, the declination-only solar-noon altitude is approximately 26.6° at the June solstice, 50.1° at an equinox and 73.5° 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 2179670 in administrative area F3, at -39.9333, 175.0500; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 26.6° at the June solstice, 50.1° at an equinox and 73.5° at the December solstice. Representative 21st-day geometry ranges from about 9.2 hours in June to 14.8 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 Whanganui?

Whanganui is represented here at approximately -39.9333, 175.0500 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 Whanganui 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.

Whanganui monthly solar geometry check for sun path

Month-by-month geometry interpretation

• 21 January: approximate solar-noon altitude 70.2° (zenith angle 19.8°) and 14.4 hours of geometric daylight. That is 0.5 hours shorter than the preceding representative date in this annual sequence.
• 21 February: approximate solar-noon altitude 61.3° (zenith angle 28.7°) and 13.3 hours of geometric daylight. That is 1.1 hours shorter than the preceding representative date in this annual sequence.
• 21 March: approximate solar-noon altitude 50.5° (zenith angle 39.5°) and 12.0 hours of geometric daylight. That is 1.2 hours shorter than the preceding representative date in this annual sequence.
• 21 April: approximate solar-noon altitude 38.5° (zenith angle 51.5°) and 10.7 hours of geometric daylight. That is 1.4 hours shorter than the preceding representative date in this annual sequence.
• 21 May: approximate solar-noon altitude 29.9° (zenith angle 60.1°) and 9.6 hours of geometric daylight. That is 1.1 hours shorter than the preceding representative date in this annual sequence.
• 21 June: approximate solar-noon altitude 26.6° (zenith angle 63.4°) and 9.2 hours of geometric daylight. That is 0.5 hours shorter than the preceding representative date in this annual sequence.
• 21 July: approximate solar-noon altitude 29.6° (zenith angle 60.4°) and 9.6 hours of geometric daylight. That is 0.4 hours longer than the preceding representative date in this annual sequence.
• 21 August: approximate solar-noon altitude 38.3° (zenith angle 51.7°) and 10.7 hours of geometric daylight. That is 1.1 hours longer than the preceding representative date in this annual sequence.
• 21 September: approximate solar-noon altitude 50.3° (zenith angle 39.7°) and 12.0 hours of geometric daylight. That is 1.4 hours longer than the preceding representative date in this annual sequence.
• 21 October: approximate solar-noon altitude 61.8° (zenith angle 28.2°) and 13.3 hours of geometric daylight. That is 1.3 hours longer than the preceding representative date in this annual sequence.
• 21 November: approximate solar-noon altitude 70.5° (zenith angle 19.5°) and 14.4 hours of geometric daylight. That is 1.1 hours longer than the preceding representative date in this annual sequence.
• 21 December: approximate solar-noon altitude 73.5° (zenith angle 16.5°) and 14.8 hours of geometric daylight. That is 0.4 hours longer than the preceding representative date in this annual sequence.

Harth calculation for latitude -39.9333°: 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.

Where can you explore related guidance?

• Explore all solar data guidance
• Sun Path: Palmerston North, New Zealand
• Sun Path: Levin, New Zealand
• Sun Path: Paraparaumu, New Zealand
• Sun Path: Porirua, New Zealand

Sources and method

Location data from the GeoNames NZ dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 2179670). Regulatory starting point: Ministry of Business, Innovation and Employment and the local council. 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

• building.govt.nz

• gml.noaa.gov