Trend Analysis and Prediction for Extreme Temperature of Lahore, Pakistan

This paper aims to examine the trends of the maximum temperature (Tmax) and minimum temperature (Tmin) in Lahore over a period of 42 years (1988 to 2029). The study employs the Mann-Kendall statistical test to analyze the linear trends of both Tmin and Tmax annually and seasonally. To determine the linear trends in temperature extremes (Te), a linear curve fitting method was employed. In modeling Tmax and Tmin, a sine function was utilized. The results showed that Tmin exhibited an increasing trend both annually and seasonally, except for winter, where no significant trend was observed. Conversely, Tmax showed a decreasing trend both annually and seasonally, except for the monsoon and pre-monsoon periods, where no significant trends were found. Furthermore, the study divided the Te data from 1988 to 2019 into twotime series: from 1988 to 2003 and from 2004 to 2019. The findings indicated that Tmin had no significant trend, while Tmax demonstrated an increasing trend for the first time series. In contrast, both Tmin and Tmax exhibited increasing trends for the second time series. Moreover, when the time series was divided into six parts for trend analysis, mixed trends, whether increasing or decreasing, were observed. To investigate the periodicity of Te, the sine function was applied, and the results showed that Tmin had no periodicity. However, Tmax exhibited periodicity, and it was observed that the peak pattern repeated in reverse after 2004. Based on the proposed sine function model, the study predicted the future pattern of the maximum temperature variation in Lahore for the next ten years (i.e., 2020 to 2029).