Background: To investigate the effect of daily meteorological factors in northeast China on coronary heart disease and explore in depth the impact of the environment on health. Methods: The population data primarily included daily coronary heart disease hospitalizations between January 1, 2015 and December 31, 2019, comprising a total of 25,461 patients. The meteorological data included daily temperature, barometric pressure, relative humidity, precipitation, and wind speed between January 1, 2015 and December 31, 2019. A multiple linear regression model was constructed for analyzing the relationship between meteorological factors and coronary heart disease.Results: After controlling for confounding factors, the mean monthly temperature negatively correlated with the monthly number of coronary heart disease hospitalizations, particularly in the warm season (Apr–Sep; β = –12.468, p < 0.05).Conclusions: In the warm season and during a mild weather, high temperature might be a protective factor against coronary heart disease.