Solar & Daylight Data
Sun Path: Kolkata, India
How to research sun path for a specific site in Kolkata — 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 IN dump](https://download.geonames.org/export/dump/IN.zip) (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 1275004). Regulatory starting point: [Bureau of Indian Standards and the applicable state or urban local body](https://www.services.bis.gov.in/php/BIS_2.0/bisconnect/knowyourstandards/Indian_standards/isdetails/). 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 Kolkata at 22.5626, 88.3630, the declination-only solar-noon altitude is approximately 89.1° at the June solstice, 67.4° at an equinox and 44.0° 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 1275004 in administrative area 28, at 22.5626, 88.3630; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 89.1° at the June solstice, 67.4° at an equinox and 44.0° at the December solstice. Representative 21st-day geometry ranges from about 10.6 hours in December to 13.4 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 Kolkata?
Kolkata is represented here at approximately 22.5626, 88.3630 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 Kolkata 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.
Kolkata monthly solar geometry check for sun path
| Representative date | Declination | Solar-noon altitude | Geometric daylight |
|---|---|---|---|
| 21 January | -20.14° | 47.3° | 10.8 h |
| 21 February | -11.23° | 56.2° | 11.4 h |
| 21 March | -0.40° | 67.0° | 12.0 h |
| 21 April | +11.58° | 79.0° | 12.7 h |
| 21 May | +20.14° | 87.6° | 13.2 h |
| 21 June | +23.45° | 89.1° | 13.4 h |
| 21 July | +20.44° | 87.9° | 13.2 h |
| 21 August | +11.75° | 79.2° | 12.7 h |
| 21 September | -0.20° | 67.2° | 12.0 h |
| 21 October | -11.75° | 55.7° | 11.3 h |
| 21 November | -20.44° | 47.0° | 10.8 h |
| 21 December | -23.45° | 44.0° | 10.6 h |
Month-by-month geometry interpretation
- 21 January: approximate solar-noon altitude 47.3° (zenith angle 42.7°) and 10.8 hours of geometric daylight. That is 0.2 hours longer than the preceding representative date in this annual sequence.
- 21 February: approximate solar-noon altitude 56.2° (zenith angle 33.8°) and 11.4 hours of geometric daylight. That is 0.5 hours longer than the preceding representative date in this annual sequence.
- 21 March: approximate solar-noon altitude 67.0° (zenith angle 23.0°) and 12.0 hours of geometric daylight. That is 0.6 hours longer than the preceding representative date in this annual sequence.
- 21 April: approximate solar-noon altitude 79.0° (zenith angle 11.0°) and 12.7 hours of geometric daylight. That is 0.7 hours longer than the preceding representative date in this annual sequence.
- 21 May: approximate solar-noon altitude 87.6° (zenith angle 2.4°) and 13.2 hours of geometric daylight. That is 0.5 hours longer than the preceding representative date in this annual sequence.
- 21 June: approximate solar-noon altitude 89.1° (zenith angle 0.9°) and 13.4 hours of geometric daylight. That is 0.2 hours longer than the preceding representative date in this annual sequence.
- 21 July: approximate solar-noon altitude 87.9° (zenith angle 2.1°) and 13.2 hours of geometric daylight. That is 0.2 hours shorter than the preceding representative date in this annual sequence.
- 21 August: approximate solar-noon altitude 79.2° (zenith angle 10.8°) and 12.7 hours of geometric daylight. That is 0.5 hours shorter than the preceding representative date in this annual sequence.
- 21 September: approximate solar-noon altitude 67.2° (zenith angle 22.8°) and 12.0 hours of geometric daylight. That is 0.7 hours shorter than the preceding representative date in this annual sequence.
- 21 October: approximate solar-noon altitude 55.7° (zenith angle 34.3°) and 11.3 hours of geometric daylight. That is 0.7 hours shorter than the preceding representative date in this annual sequence.
- 21 November: approximate solar-noon altitude 47.0° (zenith angle 43.0°) and 10.8 hours of geometric daylight. That is 0.5 hours shorter than the preceding representative date in this annual sequence.
- 21 December: approximate solar-noon altitude 44.0° (zenith angle 46.0°) and 10.6 hours of geometric daylight. That is 0.2 hours shorter than the preceding representative date in this annual sequence.
Harth calculation for latitude 22.5626°: Cooper declination approximation, 90° - |latitude - declination| at solar noon, and centre-to-centre sunrise hour angle. See NOAA's solar calculation details for fuller method context. This screening table excludes equation-of-time/civil-time conversion, atmospheric refraction, terrain, facade azimuth and obstructions; it is not an hourly shading result.
Where can you explore related guidance?
- Explore all solar data guidance
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- Sun Path: Dhanbad, India
- Sun Path: Patna, India
- Sun Path: Varanasi, India
Sources and method
Location data from the GeoNames IN dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 1275004). Regulatory starting point: Bureau of Indian Standards and the applicable state or urban local body. 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 Kolkata establish?
The sun path record for Kolkata establishes a reproducible discovery point at 22.5626, 88.3630 (GeoNames ID 1275004, administrative area 28) and a India 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 Kolkata?
For the sun path record in Kolkata, replace the 22.5626, 88.3630 city reference with the surveyed site or parcel, identify the competent local authority, and verify the current documents under National Building Code of India plus state and urban-local-body rules. Record the edition, retrieval date, units, assumptions and named checker before relying on the result.
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