Weather observation data of North China from 1973 to 2012 were investigated to analyze long term variation trend of haze related meteorological conditions. The Mann-Kendall test was utilized to analyze their variation trends and mutation points. It is uncovered that there is notable reduction in wind speed during past decades, which is adverse for diffusion of haze and could contribute to escalating frequency and intensity of haze. The escalated surface temperature in winter results in the reduction in heating day and heating degree days (HDD) and the associated reduction in heating demand and the air pollution under the context of climate change. However, heating degree days in some sites do not decline due to extreme cold waves. The effect of reduction in Heating days and HDD on heating demand and air pollution in winter has been weakened due to fix 120 heating days policy. Moreover, HDD calculated with a fixed date of heating in Beijing and Taiyuan escalates a little. Since heating days of warm cities in the south and coastal North China are lower than 120 days, implementation of a flexible heating policy in these cities could reduce heating demand and air pollution at large.