Clearness index, Beyla

Beyla, Guinea
2021-2025
Daily
dimensionless
NASA POWER

Mean: 0.533 dimensionless
Seasonal range: 0.222 dimensionless
Highest: January (0.642)
Lowest: August (0.420)
Year-to-year variability: ± 0.004 (0.8 %)
Values: 1,826 days

Monthly means of the daily values.

Period mean

Drag across the chart to zoom, double-click to reset.

Clearness index, dimensionless
Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
2025	0.600	0.573	0.548	0.531	0.540	0.496	0.443	0.419	0.483	0.558	0.565	0.591	0.529
2024	0.642	0.600	0.534	0.560	0.515	0.463	0.437	0.417	0.463	0.502	0.649	0.655	0.536
2023	0.631	0.554	0.542	0.556	0.508	0.466	0.472	0.455	0.513	0.502	0.559	0.648	0.534
2022	0.651	0.596	0.520	0.541	0.509	0.491	0.447	0.420	0.452	0.517	0.593	0.609	0.529
2021	0.643	0.567	0.519	0.530	0.528	0.516	0.428	0.451	0.490	0.547	0.612	0.618	0.537
Median	0.642	0.573	0.534	0.541	0.515	0.491	0.443	0.420	0.483	0.517	0.593	0.618
P10	0.613	0.559	0.519	0.530	0.508	0.464	0.432	0.418	0.456	0.502	0.561	0.598
P90	0.648	0.598	0.546	0.558	0.535	0.508	0.462	0.454	0.504	0.554	0.634	0.652
Min.	0.600	0.554	0.519	0.530	0.508	0.463	0.428	0.417	0.452	0.502	0.559	0.591
Max.	0.651	0.600	0.548	0.560	0.540	0.516	0.472	0.455	0.513	0.558	0.649	0.655

CSV file

1,826 rows, 45 KB. Columns: period, value, unit, confidence level, status.

date,valeur,unite,niveau_confiance,statut
2021-01-01,0.68,1,B,brut
2021-01-02,0.64,1,B,brut
2021-01-03,0.59,1,B,brut

Download the CSV

API

The same series, versioned, with a free key.

curl -H "Authorization: Bearer kuma_votre_cle" \
  "https://api.kumascience.com/v1/series/gin_beyla_kt_nasa_power_2021_2025?format=csv"

Try it in the console

Python

Read the published file directly with pandas.

import pandas as pd

url = "https://kumascience.com/data/guinee/beyla/kt_nasa_power_journalier_2411.csv"
df = pd.read_csv(url)
df.head()

Open the Python workbench

Same variable, other sources

2 series published for this variable in Beyla. The gap compares period means, which do not always cover the same years.

Source	Period	Step	Mean (dimensionless)	Gap	0.5310.533
NASA POWER	2001-2020	monthly	0.531	−0.4 %
NASA POWER this record	2021-2025	daily	0.533	reference

Notes

Source: NASA POWER, Prediction Of Worldwide Energy Resources : Solar and Meteorological Data Archive
Method: Satellite model
Unit: dimensionless
Time step: Daily, charts and table as monthly means
Period: 2021-01-01 - 2025-12-31
Kuma qualification: Acceptable qualification, cross-check series
Source licence: NASA Open Data Policy, domaine public, citation recommandée
Kuma licence: CC-BY 4.0, DOI 10.5281/zenodo.21051755

Distribution

Seasonal and monthly variability

Distribution

Monthly distribution (Tukey boxplot)

Distribution of values, month by month

Each box shows the spread for one month: the thick bar is the median value, the box covers the central half of the values. Highest typical value in December (0.65), lowest in August (0.43). Source: NASA POWER, Prediction Of Worldwide Energy Resources : Solar and Meteorological Data Archive.

Bivariate relations

Correlations between variables

Relation

KT vs GHI

KT vs GHI, R² = 0.899 (very strong correlation)

N = 1,826 daily pairs aligned by date. Least-squares linear regression: y = 0.108 · x − 0.032 (GHI in kWh/m²/day, KT dimensionless). Source: NASA POWER.

Relation

KT vs DNI

KT vs DNI, R² = 0.858 (very strong correlation)

N = 1,826 daily pairs aligned by date. Least-squares linear regression: y = 0.056 · x + 0.361 (DNI in kWh/m²/day, KT dimensionless). Source: NASA POWER.

Cite this series

Kuma Science (2026). Clearness index, Beyla (Guinea), 2021-2025. NASA POWER series, Guinea national energy data reference. DOI 10.5281/zenodo.21051755. https://kumascience.com/en/donnees/gin_beyla_kt_nasa_power_2021_2025

@misc{kuma_gin_beyla_kt_nasa_power_2021_2025,
  author       = {{Kuma Science}},
  title        = {Clearness index, Beyla (Guinea), 2021-2025},
  year         = {2026},
  howpublished = {NASA POWER series},
  doi          = {10.5281/zenodo.21051755},
  url          = {https://kumascience.com/en/donnees/gin_beyla_kt_nasa_power_2021_2025},
  note         = {License CC-BY 4.0}
}

TY  - DATA
AU  - Kuma Science
TI  - Clearness index, Beyla (Guinea), 2021-2025
PY  - 2026
PB  - Kuma Science
DO  - 10.5281/zenodo.21051755
UR  - https://kumascience.com/en/donnees/gin_beyla_kt_nasa_power_2021_2025
N1  - NASA POWER
ER  -

Also cite the primary source, whose licence applies to the published values.

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