OBJECTIVE: The purpose of this study was to investigate the influence of weather on the occurrence of acute ST-elevation myocardial infarction in Chinese subjects. METHODS: Weather and climate data, as well as the occurrence of STEMI, were monitored at 2 am, 8 am, 2 pm, and 8 pm between 2003 and 2010. Generalized additive Poisson models were utilized to plot the numbers of patients with STEMI within 6 hour intervals against climatological variations, after accounting for the effects of the hour and season. RESULTS: The inclusion of meteorological conditions, including observed atmospheric pressure (hPa, hectopascal) variations during the previous three hours and temperature ( degrees C, degrees Celsius), significantly affected the occurrence of STEMI, as measured every six hours. Compared with the 50th percentile of atmospheric pressure variations, the RRs (95% CI) for the first percentile, 10th percentile, 25th percentile, 75th percentile, 90th percentile, and 99th percentile of atmospheric pressure variation over lag 0 were 1.66 (1.36 approximately 2.03), 1.47 (1.30 approximately 1.67), 1.22 (1.12 approximately 1.33), 1.16 (1.07 approximately 1.25), 1.27 (1.13 approximately 1.43), and 1.16 (0.92 approximately 1.46), respectively. Compared to the 50th percentile of temperature, the RRs (95% CI) for the first percentile, 10th percentile, 25th percentile, 75th percentile, 90th percentile, and 99th percentile of temperature over lag 0 were 0.58 (0.40 approximately 0.83), 0.60 (0.46 approximately 0.78), 0.69 (0.57 approximately 0.83), 1.33 (1.14 approximately 1.56), 1.39 (1.13 approximately 1.71), and 1.17 (0.84 approximately 1.63), respectively. CONCLUSIONS: Based on the eight-year, single-center study, significant relationships were observed among the occurrence of STEMI and atmospheric pressure variations during the previous three hours and temperature after account for long-term time trends.