Climate change can have significant impacts on maize (Zea mays L.) grain yield. In this study, we used extensive multi-year field experimental data (n = 423) across different climatic regions of China to distinguish effects of different climate factors on maize grain yield and mimicking the effect of climate change, in particular, temperature and solar radiation. Across the years and climatic regions, the major driver for the yield difference was found to be the diurnal temperature range (DTR) and accumulated photosynthetically active radiation (PAR). 1 °C decrease in DTR and 100 MJ decrease in accumulated PAR resulted in 1.0 t ha⁻¹ and 0.85 t ha⁻¹ reduction in maize grain yield, respectively. 1 °C increase in growing season mean temperature (Tmean) and minimum temperature (Tmin) resulted in 0.83 t ha⁻¹ and 0.67 t ha⁻¹ maize grain yield reduction. By mimicking the effect of climate change on maize grain yield, it was found that 1 °C increase in Tmean resulted in 0.83 t ha⁻¹ (5.8%) maize grain yield reduction. Decrease in PAR also decreased maize grain yield significantly and the 1% decrease in PAR decreased maize grain yield by 0.15 tons per ha. Among all the five cultivars in this study, yield reductions of ZD958 and NH101 induced by 1 °C increase in Tmean were the smallest compared to other three cultivars. The quantitative analysis can provide important guidance to predict possible quantitative outcomes of future changes in crop productivity due to climate change and search for effective mitigation strategies such as cultivar selection.