Kavi (2026) Climate change and variability: an analysis of trends in rainfall and temperature in the Volta and Northern Regions of Ghana

Identification

• Journal: Theoretical and Applied Climatology
• Year: 2026
• Date: 2026-03-14
• Authors: Francis Kastro Kavi
• DOI: 10.1007/s00704-026-06156-4

Research Groups

Department of Agricultural Science Education, University of Education Winneba, Winneba, Ghana

Short Summary

This study analyzed climate change and variability in the Volta and Northern Regions of Ghana over a 39-year period (1984–2023), focusing on temperature and rainfall trends and their implications for agriculture. Findings reveal a statistically significant decreasing rainfall trend in the Northern Region and significant upward trends in both maximum and minimum temperatures across both regions, indicating a warming climate with risks for agricultural productivity.

Objective

• To analyze historical trends and variability in rainfall and temperature in the Volta and Northern Regions of Ghana over a 39-year period (1984–2023) and identify potential adaptation and mitigation strategies based on these climate trends.

Study Configuration

• Spatial Scale: Volta Region (including Volta and Oti Regions) and Northern Region (including Northern, Savannah, and North East Regions) of Ghana. Data from six weather stations (Kete-Krachi, Ho, Akatsi in Volta; Bole, Tamale, Yendi in Northern).
• Temporal Scale: 39-year period (1984–2023).

Methodology and Data

• Models used: Descriptive statistics (mean, standard deviation, coefficient of variation), Mann-Kendall Test, Sen’s Slope Estimator, Modified Mann-Kendall test, lag-1 serial correlation test, Standard Normal Homogeneity Test (SNHT). Analyses performed using R software (version 4.4.1) with "modifiedmk" and "Trend" packages.
• Data sources: Secondary data obtained from the Ghana Meteorological Agency, including historical records of annual rainfall (in millimeters), maximum temperature (in degrees Celsius), and minimum temperature (in degrees Celsius).

Main Results

• Rainfall: The Volta Region recorded a higher mean annual rainfall (1333.11 mm) with greater variability (coefficient of variation of 16.8%) compared to the Northern Region (982.29 mm mean annual rainfall, 14.3% coefficient of variation). The Volta Region showed an increasing but statistically insignificant rainfall trend, while the Northern Region exhibited a statistically significant decreasing rainfall trend. Both regions displayed pronounced interannual rainfall variability with extreme wet and dry years.
• Temperature: Both the Volta and Northern Regions experienced significant upward trends in maximum and minimum temperatures. Sen’s slope estimates indicated faster increases in minimum temperature, suggesting night-time warming. This warming climate poses risks such as increased evaporation, prolonged droughts, and reduced agricultural productivity.
• Data Homogeneity: The Standard Normal Homogeneity Test (SNHT) confirmed that the majority of data points were homogeneous, ensuring the reliability of the trend analysis despite a few identified inhomogeneous points (e.g., Volta rainfall in 1999, Northern rainfall in 1993).

Contributions

• Fills a knowledge gap by providing localized, long-term climate variability analysis for the Volta and Northern Regions of Ghana, which is crucial for region-specific agricultural planning.
• Offers evidence-based insights into climatic conditions to inform resilience-building efforts among farmers and policymakers.
• Contributes to a better understanding of climate variability to support sustainable agricultural practices, early warning systems, and climate adaptation policies at regional and national levels.

Funding

No funding was received; the study was solely funded by the author.

Citation

@article{Kavi2026Climate,
  author = {Kavi, Francis Kastro},
  title = {Climate change and variability: an analysis of trends in rainfall and temperature in the Volta and Northern Regions of Ghana},
  journal = {Theoretical and Applied Climatology},
  year = {2026},
  doi = {10.1007/s00704-026-06156-4},
  url = {https://doi.org/10.1007/s00704-026-06156-4}
}