Sun Path: Athi River, Kenya

Direct answer

For Athi River at -1.4563, 36.9783, the declination-only solar-noon altitude is approximately 65.1° at the June solstice, 88.5° at an equinox and 68.0° 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 200787 in administrative area 31, at -1.4563, 36.9783; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 65.1° at the June solstice, 88.5° at an equinox and 68.0° at the December solstice. Representative 21st-day geometry ranges from about 11.9 hours in June to 12.1 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 Athi River?

Athi River is represented here at approximately -1.4563, 36.9783 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 Athi River site remain authoritative.

Athi River monthly solar geometry check for sun path

Athi River solar-geometry fingerprint at -1.4563, 36.9783

• Athi River, 21 January: declination -20.14°, noon altitude 71.32°, zenith 18.68°, geometric daylight 12.071 hours, and vertical-object noon shadow ratio 0.338.
• Athi River, 21 February: declination -11.23°, noon altitude 80.23°, zenith 9.77°, geometric daylight 12.039 hours, and vertical-object noon shadow ratio 0.172.
• Athi River, 21 March: declination -0.40°, noon altitude 88.95°, zenith 1.05°, geometric daylight 12.001 hours, and vertical-object noon shadow ratio 0.018.
• Athi River, 21 April: declination +11.58°, noon altitude 76.96°, zenith 13.04°, geometric daylight 11.960 hours, and vertical-object noon shadow ratio 0.232.
• Athi River, 21 May: declination +20.14°, noon altitude 68.41°, zenith 21.59°, geometric daylight 11.929 hours, and vertical-object noon shadow ratio 0.396.
• Athi River, 21 June: declination +23.45°, noon altitude 65.09°, zenith 24.91°, geometric daylight 11.916 hours, and vertical-object noon shadow ratio 0.464.
• Athi River, 21 July: declination +20.44°, noon altitude 68.10°, zenith 21.90°, geometric daylight 11.928 hours, and vertical-object noon shadow ratio 0.402.
• Athi River, 21 August: declination +11.75°, noon altitude 76.79°, zenith 13.21°, geometric daylight 11.960 hours, and vertical-object noon shadow ratio 0.235.
• Athi River, 21 September: declination -0.20°, noon altitude 88.75°, zenith 1.25°, geometric daylight 12.001 hours, and vertical-object noon shadow ratio 0.022.
• Athi River, 21 October: declination -11.75°, noon altitude 79.70°, zenith 10.30°, geometric daylight 12.040 hours, and vertical-object noon shadow ratio 0.182.
• Athi River, 21 November: declination -20.44°, noon altitude 71.01°, zenith 18.99°, geometric daylight 12.072 hours, and vertical-object noon shadow ratio 0.344.
• Athi River, 21 December: declination -23.45°, noon altitude 68.01°, zenith 21.99°, geometric daylight 12.084 hours, and vertical-object noon shadow ratio 0.404.

Harth computed the Athi River fingerprint for latitude -1.4563° with the Cooper declination approximation, 90° - |latitude - declination| at solar noon, centre-to-centre sunrise hour angle and 1 / tan(altitude) shadow ratio. Longitude 36.9783° 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: Kitengela, Kenya
• Sun Path: Mlolongo, Kenya
• Sun Path: Ongata Rongai, Kenya
• Sun Path: Nairobi, Kenya
• All solar & daylight data guidance for Kenya
• Climate Design Data: Athi River, Kenya

Sources and method

Location data from the GeoNames KE dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 200787). Regulatory starting point: National Construction Authority and the applicable county government. 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

• nca.go.ke

• gml.noaa.gov