Solar & Daylight Data

Updated 2026-09-02

Solar Altitude & Azimuth: Matuga, Kenya

How to research solar altitude & azimuth for a specific site in Matuga — the controlling authority, source documents, and checks to run before you rely on a number.

Last updated September 2, 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 187269). 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. Project-date refinement reference: [NREL Solar Position Algorithm](https://midcdmz.nrel.gov/spa/).

Direct answer

For Matuga at -4.1680, 39.5707, the declination-only solar-noon altitude is approximately 62.4° at the June solstice, 85.8° at an equinox and 70.7° 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 187269 in administrative area 28, at -4.1680, 39.5707; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 62.4° at the June solstice, 85.8° at an equinox and 70.7° at the December solstice. Representative 21st-day geometry ranges from about 11.8 hours in June to 12.2 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 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 Matuga?

Matuga is represented here at approximately -4.1680, 39.5707 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.
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 solar-angle-workflow page is a project-starting worksheet, not a design value or approval. The controlling authority and qualified professionals for the Matuga site remain authoritative.

Matuga apparent-solar-time altitude and azimuth matrix

Representative dateApparent solar timeHour angleAltitudeAzimuth from north
21 January08:00-60°29.55°110.82°
21 January10:00-30°56.72°121.20°
21 January12:00+0°74.03°180.00°
21 January14:00+30°56.72°238.80°
21 January16:00+60°29.55°249.18°
21 February08:00-60°30.22°100.57°
21 February10:00-30°59.47°105.11°
21 February12:00+0°82.94°180.00°
21 February14:00+30°59.47°254.89°
21 February16:00+60°30.22°259.43°
21 March08:00-60°29.95°88.06°
21 March10:00-30°59.79°83.62°
21 March12:00+0°86.24°0.00°
21 March14:00+30°59.79°276.38°
21 March16:00+60°29.95°271.94°
21 April08:00-60°28.29°74.47°
21 April10:00-30°56.26°61.87°
21 April12:00+0°74.25°0.00°
21 April14:00+30°56.26°298.13°
21 April16:00+60°28.29°285.53°
21 May08:00-60°26.31°65.10°
21 May10:00-30°51.80°49.39°
21 May12:00+0°65.69°0.00°
21 May14:00+30°51.80°310.61°
21 May16:00+60°26.31°294.90°
21 June08:00-60°25.38°61.56°
21 June10:00-30°49.77°45.26°
21 June12:00+0°62.38°0.00°
21 June14:00+30°49.77°314.74°
21 June16:00+60°25.38°298.44°
21 July08:00-60°26.22°64.77°
21 July10:00-30°51.62°49.00°
21 July12:00+0°65.39°0.00°
21 July14:00+30°51.62°311.00°
21 July16:00+60°26.22°295.23°
21 August08:00-60°28.26°74.27°
21 August10:00-30°56.18°61.59°
21 August12:00+0°74.08°0.00°
21 August14:00+30°56.18°298.41°
21 August16:00+60°28.26°285.73°
21 September08:00-60°29.93°87.83°
21 September10:00-30°59.77°83.22°
21 September12:00+0°86.03°0.00°
21 September14:00+30°59.77°276.78°
21 September16:00+60°29.93°272.17°
21 October08:00-60°30.20°101.18°
21 October10:00-30°59.36°106.13°
21 October12:00+0°82.41°180.00°
21 October14:00+30°59.36°253.87°
21 October16:00+60°30.20°258.82°
21 November08:00-60°29.52°111.17°
21 November10:00-30°56.59°121.70°
21 November12:00+0°73.73°180.00°
21 November14:00+30°56.59°238.30°
21 November16:00+60°29.52°248.83°
21 December08:00-60°29.11°114.59°
21 December10:00-30°55.22°126.48°
21 December12:00+0°70.72°180.00°
21 December14:00+30°55.22°233.52°
21 December16:00+60°29.11°245.41°

How to use the Matuga angle matrix

The matrix fixes latitude -4.1680° and records longitude 39.5707°, 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.

Sources and method

Location data from the GeoNames KE dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 187269). 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. Project-date refinement reference: NREL Solar Position Algorithm.

Frequently asked questions

What does the solar altitude and azimuth record for Matuga establish?

The solar altitude and azimuth record for Matuga establishes a reproducible discovery point at -4.1680, 39.5707 (GeoNames ID 187269, administrative area 28) and a Kenya source path. It does not establish a final project value, approval or parcel decision.

What must be replaced before using this solar altitude and azimuth workflow for a project in Matuga?

For the solar altitude and azimuth record in Matuga, replace the -4.1680, 39.5707 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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