journal article Open Access Feb 09, 2026

Compound Hot‐Dry Days ( CHDDs ) and Their Implications on Maize Yields in the Free State Province, South Africa

View at Publisher Save 10.1002/joc.70281
Abstract
ABSTRACT

Compound occurrence of extreme weather events and their impacts on agriculture have been widely investigated in many regions except for South Africa. This study explores the variability of compound hot‐dry days (CHDDs) using daily rainfall and temperature data from 1950 to 2023 in the Free State Province. Their trends over time are determined for different 30‐year periods starting in 1950. The effect of El Niño Southern Oscillation (ENSO) on the CHDDs was also investigated. To determine the impact of extreme events on food security, the study evaluated an association between CHDDs and maize yields. The results show significant (
p
 < 0.05) increasing trends in CHDDs. 30‐year period trends starting in 1950 were mostly not significant (
p
 < 0.05) except for isolated cases in Bloemfontein and Bothaville. Correlations between CHDDs and Oceanic Niño Index showed significant (
p
 < 0.01) positive Pearson correlation. Generally, during El Niño years, the frequency of CHDDs was high in all the stations with the maximum exceeding 140 CHDDs obtained in the 2015/16 season. In contrast, most of the years in which the frequency of CHDDs was below 40 occurred in La Niña years. In addition, CHDDs had a significant (
p
 < 0.01) negative correlation with yield anomalies. The results also showed extremely high negative yield anomalies during El Niño years, while most of the years of extremely high positive yield anomalies occurred in neutral years. The results clearly show linkages between ENSO and CHDDs increasing the likelihood of a reasonable forecast of seasonal CHDDs especially in South Africa where the past results have shown high predictability of the ENSO index. The significant association of CHDDs with maize yields is a factor that can be helpful in projecting the scale of food security and level of international commodity trade for the country. The agricultural sector needs to improve agricultural systems resilience against compound extreme weather events across several commodities.
Topics

No keywords indexed for this article. Browse by subject →

References
55
[4]
DALRRD.2023.Abstract of Agricultural Statistics South Africa 2023.https://old.dalrrd.gov.za/Portals/0/Statistics%20and%20Economic%20Analysis/Statistical%20Information/Abstract%202023.pdf.
[8]
FAOSTAT.2025.Crop and Livestock Products.https://www.fao.org/faostat/en/#data/QCL.
[26]
Excessive rainfall leads to maize yield loss of a comparable magnitude to extreme drought in the United States

Yan Li, Kaiyu Guan, Gary D. Schnitkey et al.

Global Change Biology 10.1111/gcb.14628
[35]
Moeletsi M. E.2010.Agroclimatological Risk Assessment of Rainfed Maize Production for the Free State Province of South Africa [University of the Free State ].https://scholar.ufs.ac.za/items/52254b64‐7167‐4f5c‐b507‐714c86c74bd7.

Showing 50 of 55 references

Metrics
0
Citations
55
References
Details
Published
Feb 09, 2026
Vol/Issue
46(5)
License
View
Funding
Agricultural Research Council
Cite This Article
Mokhele Moeletsi, Mitsuru Tsubo (2026). Compound Hot‐Dry Days ( CHDDs ) and Their Implications on Maize Yields in the Free State Province, South Africa. International Journal of Climatology, 46(5). https://doi.org/10.1002/joc.70281