Note: A lower RMSE indicates a higher model accuracy. ‘Simple tavg’ in the figure refers to the model with linear and squared terms for average temperature and total precipitation calculated over the entire growing season (October to May). ‘Seasonal tavg’ means the model with linear and squared terms for seasonal (Fall, Winter and Spring) average temperature and seasonal total precipitation. ‘Simple dd’ refers to the model that includes linear and squared terms for growing degree-days and a linear term for freezing days, respectively, computed above and below the threshold temperature of 0°C over the entire growing period along with the total precipitation variable. ‘Seasonal dd’ represents the model that includes linear and squared terms for degree-day variables defined for each season (Fall, Winter and Spring) based on the threshold temperature of 0°C along with seasonal freezing and precipitation variables.