Solar & Daylight Data

Updated 2026-08-31

Sun Path: Nairobi, Kenya

How to research sun path for a specific site in Nairobi — 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 KE dump](https://download.geonames.org/export/dump/KE.zip) (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 184745). Regulatory starting point: [National Construction Authority and the applicable county government](https://www.nca.go.ke/). 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 Nairobi at -1.2833, 36.8167, the declination-only solar-noon altitude is approximately 65.3° at the June solstice, 88.7° at an equinox and 67.8° 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 184745 in administrative area 05, at -1.2833, 36.8167; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 65.3° at the June solstice, 88.7° at an equinox and 67.8° 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 Nairobi?

Nairobi is represented here at approximately -1.2833, 36.8167 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.
InputProject-specific evidenceQA question
Sitesurveyed coordinates, elevation and horizonDoes the point represent the building?
Weather/solar methodnamed dataset, algorithm, period and time basisAre station, time zone and units explicit?
Design scenariocurrent and future scenario agreed by the teamIs an average being mistaken for an extreme?
Complianceadopted local document and editionWas 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 Nairobi site remain authoritative.

Nairobi monthly solar geometry check for sun path

Representative dateDeclinationSolar-noon altitudeGeometric daylightNoon shadow / height
21 January-20.14°71.15°12.063 h0.341
21 February-11.23°80.06°12.034 h0.175
21 March-0.40°89.12°12.001 h0.015
21 April+11.58°77.14°11.965 h0.228
21 May+20.14°68.58°11.937 h0.392
21 June+23.45°65.27°11.926 h0.461
21 July+20.44°68.28°11.936 h0.398
21 August+11.75°76.96°11.964 h0.232
21 September-0.20°88.92°12.001 h0.019
21 October-11.75°79.53°12.036 h0.185
21 November-20.44°70.84°12.064 h0.347
21 December-23.45°67.83°12.074 h0.407

Nairobi solar-geometry fingerprint at -1.2833, 36.8167

  • Nairobi, 21 January: declination -20.14°, noon altitude 71.15°, zenith 18.85°, geometric daylight 12.063 hours, and vertical-object noon shadow ratio 0.341.
  • Nairobi, 21 February: declination -11.23°, noon altitude 80.06°, zenith 9.94°, geometric daylight 12.034 hours, and vertical-object noon shadow ratio 0.175.
  • Nairobi, 21 March: declination -0.40°, noon altitude 89.12°, zenith 0.88°, geometric daylight 12.001 hours, and vertical-object noon shadow ratio 0.015.
  • Nairobi, 21 April: declination +11.58°, noon altitude 77.14°, zenith 12.86°, geometric daylight 11.965 hours, and vertical-object noon shadow ratio 0.228.
  • Nairobi, 21 May: declination +20.14°, noon altitude 68.58°, zenith 21.42°, geometric daylight 11.937 hours, and vertical-object noon shadow ratio 0.392.
  • Nairobi, 21 June: declination +23.45°, noon altitude 65.27°, zenith 24.73°, geometric daylight 11.926 hours, and vertical-object noon shadow ratio 0.461.
  • Nairobi, 21 July: declination +20.44°, noon altitude 68.28°, zenith 21.72°, geometric daylight 11.936 hours, and vertical-object noon shadow ratio 0.398.
  • Nairobi, 21 August: declination +11.75°, noon altitude 76.96°, zenith 13.04°, geometric daylight 11.964 hours, and vertical-object noon shadow ratio 0.232.
  • Nairobi, 21 September: declination -0.20°, noon altitude 88.92°, zenith 1.08°, geometric daylight 12.001 hours, and vertical-object noon shadow ratio 0.019.
  • Nairobi, 21 October: declination -11.75°, noon altitude 79.53°, zenith 10.47°, geometric daylight 12.036 hours, and vertical-object noon shadow ratio 0.185.
  • Nairobi, 21 November: declination -20.44°, noon altitude 70.84°, zenith 19.16°, geometric daylight 12.064 hours, and vertical-object noon shadow ratio 0.347.
  • Nairobi, 21 December: declination -23.45°, noon altitude 67.83°, zenith 22.17°, geometric daylight 12.074 hours, and vertical-object noon shadow ratio 0.407.

Harth computed the Nairobi fingerprint for latitude -1.2833° with the Cooper declination approximation, 90° - |latitude - declination| at solar noon, centre-to-centre sunrise hour angle and 1 / tan(altitude) shadow ratio. Longitude 36.8167° 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.

Sources and method

Location data from the GeoNames KE dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 184745). 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.

Frequently asked questions

What does the sun path record for Nairobi establish?

The sun path record for Nairobi establishes a reproducible discovery point at -1.2833, 36.8167 (GeoNames ID 184745, administrative area 05) and a Kenya 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 Nairobi?

For the sun path record in Nairobi, replace the -1.2833, 36.8167 city reference with the surveyed site or parcel, identify the competent local authority, and verify the current documents under National Building Code and county development-control requirements. Record the edition, retrieval date, units, assumptions and named checker before relying on the result.

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