Sun Path: London, Canada

Direct answer

For London at 42.9834, -81.2330, the declination-only solar-noon altitude is approximately 70.5° at the June solstice, 47.0° at an equinox and 23.6° 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 6058560 in administrative area 08, at 42.9834, -81.2330; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 70.5° at the June solstice, 47.0° at an equinox and 23.6° at the December solstice. Representative 21st-day geometry ranges from about 8.8 hours in December to 15.2 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 London?

London is represented here at approximately 42.9834, -81.2330 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

Month-by-month geometry interpretation

• 21 January: approximate solar-noon altitude 26.9° (zenith angle 63.1°) and 9.3 hours of geometric daylight. That is 0.5 hours longer than the preceding representative date in this annual sequence.
• 21 February: approximate solar-noon altitude 35.8° (zenith angle 54.2°) and 10.6 hours of geometric daylight. That is 1.2 hours longer than the preceding representative date in this annual sequence.
• 21 March: approximate solar-noon altitude 46.6° (zenith angle 43.4°) and 11.9 hours of geometric daylight. That is 1.4 hours longer than the preceding representative date in this annual sequence.
• 21 April: approximate solar-noon altitude 58.6° (zenith angle 31.4°) and 13.5 hours of geometric daylight. That is 1.5 hours longer than the preceding representative date in this annual sequence.
• 21 May: approximate solar-noon altitude 67.2° (zenith angle 22.8°) and 14.7 hours of geometric daylight. That is 1.2 hours longer than the preceding representative date in this annual sequence.
• 21 June: approximate solar-noon altitude 70.5° (zenith angle 19.5°) and 15.2 hours of geometric daylight. That is 0.5 hours longer than the preceding representative date in this annual sequence.
• 21 July: approximate solar-noon altitude 67.5° (zenith angle 22.5°) and 14.7 hours of geometric daylight. That is 0.5 hours shorter than the preceding representative date in this annual sequence.
• 21 August: approximate solar-noon altitude 58.8° (zenith angle 31.2°) and 13.5 hours of geometric daylight. That is 1.2 hours shorter than the preceding representative date in this annual sequence.
• 21 September: approximate solar-noon altitude 46.8° (zenith angle 43.2°) and 12.0 hours of geometric daylight. That is 1.5 hours shorter than the preceding representative date in this annual sequence.
• 21 October: approximate solar-noon altitude 35.3° (zenith angle 54.7°) and 10.5 hours of geometric daylight. That is 1.5 hours shorter than the preceding representative date in this annual sequence.
• 21 November: approximate solar-noon altitude 26.6° (zenith angle 63.4°) and 9.3 hours of geometric daylight. That is 1.2 hours shorter than the preceding representative date in this annual sequence.
• 21 December: approximate solar-noon altitude 23.6° (zenith angle 66.4°) and 8.8 hours of geometric daylight. That is 0.5 hours shorter than the preceding representative date in this annual sequence.

Harth calculation for latitude 42.9834°: 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: Guelph, Canada
• Sun Path: Hamilton, Canada
• Sun Path: Burlington, Canada
• Sun Path: Oakville, Canada

Sources and method

Location data from the GeoNames CA dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 6058560). Regulatory starting point: Codes Canada and the applicable provincial or territorial 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

• nrc.canada.ca

• gml.noaa.gov