Indian agriculture would suffer from elevated temperature and drought during the second part of this century, due to climate change. Weeds respond quickly to stress and adapt to the environment faster than crops. In this context, an experiment was carried out in growth chamber during 2015-16 with an objective to evaluate the effect of increase in air temperature and variations in soil moisture on Cyperus rotundus L. (purple nutsedge). A complete randomized design with 10 treatments and three replications was used for this pot culture experiment. The C. rotundus plants were grown for three generations. The treatments comprised of three temperature levels, viz. daily ambient (control), ambient +2oC and ambient +4oC increase over the ambient and two soil moisture levels, viz. soil moisture provision at 100 per cent of evaporation (M100) and 60 per cent of evaporation (M60). The combination of treatment were imposed at all stages of growth.   C. rotundus had high acclimatization capacity and better growth   under elevated temperature up to +4oC and under sufficient moisture due to its C4 pathway, which helped the weed to utilize the moisture and temperature more efficiently even during stress and record higher growth. It is concluded that, at projected future temperature (up to +4oC), C. rotundus may become more problematic, particularly during the rainy season.