Decadal Trend Analysis of Maximum Temperature at Nagpur District of Maharashtra, India

Abstract

An attempt was made for decadal trend analysis of maximum temperature for monthly, seasonal and annual time series over a period of 1985 to 2024 using the Mann-Kendall Test and Sen’s Slope Estimator method at Nagpur district of Maharashtra. The annual trend in maximum temperatures from 1985 to 2024 showed non-significant increase of 0.004°C. Significant increase of maximum temperature was observed during Northeast monsoon season at 90% confidence level, with a rise of 0.025°C. Winter and summer temperatures exhibit minor, non-significant decreases. Among the months, November showed significant increase of 0.024°C.  Between 1985 and 1994, the annual maximum temperatures showed no significant trend. The SW Monsoon experienced non-significant decrease of 0.025°C, while the NE Monsoon season showed a non-significant increase of 0.033°C. Winter recorded increase of 0.088°C, while summer showed no trend. January noticed non-significant increase of 0.238°C. From 1995 to 2004, a statistically significant annual increase of 0.100°C was observed. The NE Monsoon and summer seasons experienced significant increasing trends, with increases of 0.220°C and 0.214°C, respectively. The SW Monsoon season, however, showed a non-significant decreasing trend of 0.150°C. April experienced a significant rise in maximum temperatures of 0.267°C, while August showed a significant decrease of 0.167°C. During 2005–2014, the annual trend showed non-significant decrease of 0.013°C. The NE Monsoon season and winter exhibited decreasing trends, with winter showing a significant decline of 0.100°C at the 90% confidence level. Monthly non-significant decreasing trends was observed during January (-0.125°C) and February (-0.133°C). For the recent decades 2015–2024, annual maximum temperatures observed, non-significant decline of 0.020°C. The SW Monsoon season exhibited, non-significant increase of 0.020°C, while the NE Monsoon and winter seasons experienced non-significant decreases. Summer showed, non-significant decreasing trend, with decline of 0.230°C. Among monthly trends, April (-0.320°C) and May (-0.230°C) exhibited the most notable non-significant decreases.