Changes in Indices of Daily Temperature and Precipitation Extremes in Northwest Nigeria

Abstract

It’s a known fact that climate change will bring about increases in the occurrence of weather extreme events such as elevated temperature, drought, and floods; most especially in areas classified as hotspots to climate change – such as northwest Nigeria. This study investigates trends in extreme temperature and precipitation indices between 1971 and 2010 for six synoptic weather stations in northwest Nigeria. Results indicate that there have been statistically significant, spatially coherent trends in temperature indices that are related to temperature increases in the region. Significant, increasing trends have been found in the annual minimum of daily maximum and minimum temperature, the annual maximum of daily maximum and minimum temperature, the number of summer nights, and the number of days where daily temperature has exceeded its 90th percentile. Significant negative trends have been found in the number of days when daily temperature is below its 10th percentile and daily temperature range. Trends in precipitation indices, including the number of days with precipitation, the average precipitation intensity, and maximum daily precipitation events, are weak in general and do not show spatial coherence, with Kaduna showing decreasing trend.

Keywords: Climate, Extremes, Trends, Temperature, Precipitation