The weather in Shijiazhuang in October

① According to the diagram, the fog turns cloudy; It means cloudy and sunny; Northwest wind level 6;

② Air pollution index refers to the degree of air pollution. The greater the index, the more serious the air pollution. The level of air quality is influenced by natural factors on the one hand and human activities on the other.

So the answer is: ① Fog turns cloudy; Cloudy to sunny; Northwest; Level 6; 2 good; Natural factors; Human activities.