Solar & Daylight Data
Sun Path: Cardiff, UK
How to research sun path for a specific site in Cardiff — 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 GB dump](https://download.geonames.org/export/dump/GB.zip) (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 2653822). Regulatory starting point: [UK and devolved building-control authorities](https://www.gov.uk/government/collections/approved-documents). 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 Cardiff at 51.4800, -3.1800, the declination-only solar-noon altitude is approximately 62.0° at the June solstice, 38.5° at an equinox and 15.1° 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 2653822 in administrative area WLS, at 51.4800, -3.1800; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 62.0° at the June solstice, 38.5° at an equinox and 15.1° at the December solstice. Representative 21st-day geometry ranges from about 7.6 hours in December to 16.4 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 Cardiff?
Cardiff is represented here at approximately 51.4800, -3.1800 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?
- Fix the surveyed site and local time basis.
- Select an authoritative weather source or a named solar-position algorithm.
- Record period, percentile or scenario and units.
- Test sensitivity to elevation, exposure, urban form and horizon.
- Save the source file, retrieval date and checker in the model record.
| Input | Project-specific evidence | QA question |
|---|---|---|
| Site | surveyed coordinates, elevation and horizon | Does the point represent the building? |
| Weather/solar method | named dataset, algorithm, period and time basis | Are station, time zone and units explicit? |
| Design scenario | current and future scenario agreed by the team | Is an average being mistaken for an extreme? |
| Compliance | adopted local document and edition | Was 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 Cardiff 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.
Cardiff monthly solar geometry check for sun path
| Representative date | Declination | Solar-noon altitude | Geometric daylight | Noon shadow / height |
|---|---|---|---|---|
| 21 January | -20.14° | 18.38° | 8.343 h | 3.009 |
| 21 February | -11.23° | 27.29° | 10.075 h | 1.938 |
| 21 March | -0.40° | 38.12° | 11.932 h | 1.275 |
| 21 April | +11.58° | 50.10° | 13.989 h | 0.836 |
| 21 May | +20.14° | 58.66° | 15.657 h | 0.609 |
| 21 June | +23.45° | 61.97° | 16.403 h | 0.532 |
| 21 July | +20.44° | 58.96° | 15.723 h | 0.602 |
| 21 August | +11.75° | 50.27° | 14.020 h | 0.831 |
| 21 September | -0.20° | 38.32° | 11.966 h | 1.265 |
| 21 October | -11.75° | 26.77° | 9.980 h | 1.983 |
| 21 November | -20.44° | 18.08° | 8.277 h | 3.063 |
| 21 December | -23.45° | 15.07° | 7.597 h | 3.714 |
Cardiff solar-geometry fingerprint at 51.4800, -3.1800
- Cardiff, 21 January: declination -20.14°, noon altitude 18.38°, zenith 71.62°, geometric daylight 8.343 hours, and vertical-object noon shadow ratio 3.009.
- Cardiff, 21 February: declination -11.23°, noon altitude 27.29°, zenith 62.71°, geometric daylight 10.075 hours, and vertical-object noon shadow ratio 1.938.
- Cardiff, 21 March: declination -0.40°, noon altitude 38.12°, zenith 51.88°, geometric daylight 11.932 hours, and vertical-object noon shadow ratio 1.275.
- Cardiff, 21 April: declination +11.58°, noon altitude 50.10°, zenith 39.90°, geometric daylight 13.989 hours, and vertical-object noon shadow ratio 0.836.
- Cardiff, 21 May: declination +20.14°, noon altitude 58.66°, zenith 31.34°, geometric daylight 15.657 hours, and vertical-object noon shadow ratio 0.609.
- Cardiff, 21 June: declination +23.45°, noon altitude 61.97°, zenith 28.03°, geometric daylight 16.403 hours, and vertical-object noon shadow ratio 0.532.
- Cardiff, 21 July: declination +20.44°, noon altitude 58.96°, zenith 31.04°, geometric daylight 15.723 hours, and vertical-object noon shadow ratio 0.602.
- Cardiff, 21 August: declination +11.75°, noon altitude 50.27°, zenith 39.73°, geometric daylight 14.020 hours, and vertical-object noon shadow ratio 0.831.
- Cardiff, 21 September: declination -0.20°, noon altitude 38.32°, zenith 51.68°, geometric daylight 11.966 hours, and vertical-object noon shadow ratio 1.265.
- Cardiff, 21 October: declination -11.75°, noon altitude 26.77°, zenith 63.23°, geometric daylight 9.980 hours, and vertical-object noon shadow ratio 1.983.
- Cardiff, 21 November: declination -20.44°, noon altitude 18.08°, zenith 71.92°, geometric daylight 8.277 hours, and vertical-object noon shadow ratio 3.063.
- Cardiff, 21 December: declination -23.45°, noon altitude 15.07°, zenith 74.93°, geometric daylight 7.597 hours, and vertical-object noon shadow ratio 3.714.
Harth computed the Cardiff fingerprint for latitude 51.4800° with the Cooper declination approximation, 90° - |latitude - declination| at solar noon, centre-to-centre sunrise hour angle and 1 / tan(altitude) shadow ratio. Longitude -3.1800° 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.
Where can you explore related guidance?
- Explore all solar data guidance
- Sun Path: Bristol, UK
- Sun Path: Swansea, UK
- Sun Path: Swindon, UK
- Sun Path: Plymouth, UK
- All solar & daylight data guidance for United Kingdom
- Climate Design Data: Cardiff, UK
Sources and method
Location data from the GeoNames GB dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 2653822). Regulatory starting point: UK and devolved building-control authorities. 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
Frequently asked questions
What does the sun path record for Cardiff establish?
The sun path record for Cardiff establishes a reproducible discovery point at 51.4800, -3.1800 (GeoNames ID 2653822, administrative area WLS) and a United Kingdom 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 Cardiff?
For the sun path record in Cardiff, replace the 51.4800, -3.1800 city reference with the surveyed site or parcel, identify the competent local authority, and verify the current documents under Building Regulations and nation-specific Approved Documents or technical handbooks. Record the edition, retrieval date, units, assumptions and named checker before relying on the result.
Related pages
- Sun Path: Caloundra, Australia
Sun path for Caloundra, Australia: solar-noon altitude 39.8° June, 63.2° equinox, 86.6° December; 10.3–13.7 h daylight; 12-month geometry table.
- Sun Path: Canberra, Australia
Sun path for Canberra, Australia: solar-noon altitude 31.3° June, 54.7° equinox, 78.2° December; 9.6–14.4 h daylight; 12-month geometry table.
- Sun Path: Cape Town, South Africa
Sun path for Cape Town, South Africa: solar-noon altitude 32.6° June, 56.1° equinox, 79.5° December; 9.7–14.3 h daylight; 12-month geometry table.
- Sun Path: Carletonville, South Africa
Sun path for Carletonville, South Africa: solar-noon altitude 40.2° June, 63.6° equinox, 87.1° December; 10.3–13.7 h daylight; 12-month geometry table.
- Sun Path: Carlow, Ireland
Sun path for Carlow, Ireland: solar-noon altitude 60.6° June, 37.2° equinox, 13.7° December; 7.3–16.7 h daylight; 12-month geometry table.
- Sun Path: Carrigaline, Ireland
Sun path for Carrigaline, Ireland: solar-noon altitude 61.6° June, 38.2° equinox, 14.8° December; 7.5–16.5 h daylight; 12-month geometry table.