Spatial variations in the trend of heatwave over West Africa

The spatial variation of heatwave occurrences and duration were considered using twelve definitions over West Africa. The definitions are based on different temperature thresholds and percentiles. Daily maximum temperatures were obtained from the high-resolution Princeton Meteorological Forcings for West/Central/East Africa data. Temperature threshold-based definitions of the heatwave were found to have more geographical spread in positive trends in heatwave number than percentile-based methods. Trends in the longest heatwave were more pronounced in the temperature threshold indices than percentile-based indices. Our results also showed that the areas with significant trends increased as the definition grew from 2 to 3 days using a temperature threshold of 35°C. The positive trends of the heatwave in the region should be a growing concern for public health officials.