The objective of this study was to illustrate the effects of climate warming on rice growth by analyzing medium-maturing medium japonica rice in southern Jiangsu. Data from local sowing date experiments were collected from the literature, and combined with meteorological data for the corresponding period to form a field warming experiment to study the effects of temperature increases caused by the different sowing dates on rice growth. The results showed that warming had a positive impact on rice growth in southern Jiangsu. All physiological indexes of rice growth were influenced by warming, and appeared to follow different trends during each growth stage. Temperature increases shortened the length of growth stages, especially the vegetative growth period. Leaf area index increment increased with increasing temperature in the sowing to jointing and jointing to heading stages, but decreased in the heading to mature stage. This showed that rising temperature accelerated the rate of leaf growth during the early rice growth period, and led to leaf premature senescence in later growth stages. The influence of temperature rising on the leaf area duration of rice showed a decreasing trend in the sowing to jointing stage and jointing to heading stage, but increased in the heading to mature stage. Dry matter accumulation increment and crop growth rate increased with temperature in all growth stages. There were several thresholds found for the effect of temperature increase on rice growth, which could be defined as temperature saturation points for rice growth. The temperature saturation points of medium-maturing medium japonica rice in southern Jiangsu appeared at 27.5°C and 23°C in the jointing to heading stage and heading to mature stage, respectively, both in the optimum temperature range.