Climate change impacts the nutritional quality of rice, a main calorie source for over 50% of the world population. Yet, the effect of rising temperature on rice metal content, both micronutrient and non-essential metals, is not well-characterized under real-world growing conditions. We analyzed brown rice samples across four cultivars and five growing seasons (2014-2019) to examine the relationship between ambient temperature and the concentrations of 16 metals. Higher temperatures were shown to be associated with lower nickel and cadmium concentrations but with higher rubidium, molybdenum, and cesium concentrations. These findings provide novel evidence for the impact of temperature on rice grain metals and demonstrate the value of multi-season, cultivar-diverse field studies. Our results also indicate the need to study a broader range of metals in climate-resilient nutrition strategies and global food security assessments.