Monthly temperature trends in major climate zones

Mann-Kendall trend test along with deterministic linear trend was applied to temperature and rainfall data during 1901 to 2002 for four climatic zones of India i.e. arid, humid, semi-arid temperate and semi-arid tropic in order to examine the trends in temperature. Figure shows the four climatic zones studied.

For Humid Zone (zone-1) temperature for January, February, March, August, October, November and December showed increasing trend. Analysis revealed that during the study period, the temperature for January has increased by 0.47°C for February 1.14°C for March 0.7°C, for August it is 0.12°C, for October it is 0.40°C, for November and December 1.22°C and 1.19°C respectively. In case of Semi-Arid-Temperate Zone (Zone-2) there is a significant increase in temperature for February, November and December. For February the increase in temperature is 1.23°C, November is 1.38°C and for December it is 1.23°C. Temperature in September showed a decreasing trend and temperature is decreasing by 0.45°C. For Semi-Arid Tropic Zone (Zone-3) temperature for January-April and then from September-December was found to be increasing. For January there is 0.52°C increase, February 1.17°C, March 0.93°C, April 0.70°C, September 0.42°C, October 0.68°C, November 1.51°C and December 1.31°C respectively. Arid Zone (Zone 4) showed an increasing trend in temperature for February, April, November and December and over the years the increase in temperature in these months is 1.18°C, 1.27°C, 0.97°C and 0.84°C respectively. For July there is a 0.81°C decrease in temperature.