Abstract: Using MICAPS data, surface meteorological observations, reanalysis of NECP data, and PM2.5 and PM10 concentration data from the Hengshui Environmental Quality Monitoring Station, the continuous smoggy weather that occurred in Hengshui, Hebei Province, in January 2013 was analyzed in terms of the changes in the concentrations of PM10 and PM2.5, the relationship between pollutant concentrations in smoggy weather and ground elements, and the circulation at the middle and lower levels. The results showed the following: 1) Concentrations of PM10 and PM2.5 were low, from 0600 LST to 0700 LST and from 1600 LST to 2100 LST; the PM10 concentration was at a maximum at 1500 LST, and the PM2.5 concentration was the highest at 0200 LST. 2) The relationship between pollutant concentrations in smoggy weather and surface humidity was not a simple positive or negative correlation. 3) The major sources of air pollution are industrial pollution, dust pollution, coal heating in winter, local pollution sources, and regional pollution in Hengshui. 4) During smoggy weather, relative humidity and visibility were negatively correlated, changes in pressure were small, and north to northeasterly winds with a wind speed of less than 2 m/s were most likely to occur. 5) The airflow at 500 hPa on heavy pollution days was primary zonal, while on less polluted days northwest airflow was strong or there was trough or ridge activity at 500 hPa. 6) During smoggy weather, there was likely to be an inversion layer below 850 hPa at 0800 LST, and the surface pressure field was weak, particularly in the Hebei Plain. Finally, the effects and countermeasures for smoggy weather are discussed.