The estimated average surface temperature using Q-Q CFM over the Cauvery river basin explains the rapid changes in climatic conditions. The study illustrates a significant increase in average surface temperature at Cauvery river basin due to global warming. The average temperature trend shows drop in the near future up to 0.5°C especially during the winter season. However, the trend rapidly increases in later years over the entire basin during summer seasons. The maximum change is observed in summer during the far future and which records the average temperature reading crossing 30°C at the lower Cauvery river basin. The maximum temperature change of 1.8°C to 2.7°C is estimated in far future time slice during summer season. The Q-Q CFM technique performs well and overcomes the drawbacks of the single change factor and other multiple change factor methods. The average temperature reading crossing a record 30°C at the lower Cauvery river basin nearing the end of the current century. The Q-Q CFM is computationally efficient and an effective technique for regional climate change assessments. The quantile to quantile change factor method is suggested to overcome the drawbacks of traditional change factor methods. © 2020 Ecological Society of India. All rights reserved.