Solar Altitude & Azimuth: 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 solar altitude and azimuth record.

Prepared by Harth · Topic-specific calculated asset and fresh SERP brief passed editorial screening; page remains noindex pending the independent content, evidence, similarity and link gates · Published 2026-08-26 · Updated 2026-09-02.

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 solar altitude and azimuth 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 solar-angle-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.

London apparent-solar-time altitude and azimuth matrix

How to use the London angle matrix

The matrix fixes latitude 42.9834° and records longitude -81.2330°, but its clock column is apparent solar time rather than civil time. Convert the project date and longitude with a reviewed solar-position implementation before transferring an angle into a model. Azimuth is clockwise from true north. Rows below the geometric horizon are retained to make the screening limit visible; refraction, terrain and obstructions can change observed sunrise and sunset.

Harth calculated this solar altitude & azimuth matrix with the Cooper declination approximation and spherical altitude/azimuth equations. It is a reproducible comparison asset, not a surveyed horizon or construction setting. Refine it with the NREL Solar Position Algorithm.

Where can you explore related guidance?

• Explore all solar data guidance
• Sun Path: London, Canada
• Solar Shading Design: London, Canada
• Daylight & Orientation: London, Canada
• Solar Altitude & Azimuth: Kitchener, Canada
• All solar & daylight data guidance for Canada
• Climate Design Data: London, 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. Project-date refinement reference: NREL Solar Position Algorithm.

Source links

• download.geonames.org

• nrc.canada.ca

• gml.noaa.gov

• midcdmz.nrel.gov