Sample_Pollution_and_wind_monthly<-mutate(Sample_Pollution_and_wind_monthly,rounded_angle1=angle1)
Sample_Pollution_and_wind_monthly$rounded_angle1<-
  cut(Sample_Pollution_and_wind_monthly$rounded_angle1, breaks = c(0,22.5,67.5,112.5,157.5,202.5,247.5,292.5,337.5,360), right = TRUE, labels=c(0,45,90,135,180,225,270,315,360) )

Sample_Pollution_and_wind_monthly<-mutate(Sample_Pollution_and_wind_monthly,rounded_angle2=angle2)
Sample_Pollution_and_wind_monthly$rounded_angle2<-
  cut(Sample_Pollution_and_wind_monthly$rounded_angle2, breaks = c(0,22.5,67.5,112.5,157.5,202.5,247.5,292.5,337.5,360), right = TRUE, labels=c(0,45,90,135,180,225,270,315,360) )
...
...

for(x in 1:31) {
  Sample_Pollution_and_wind_monthly<-mutate(Sample_Pollution_and_wind_monthly,rounded_anglex=anglex)
  Sample_Pollution_and_wind_monthly$rounded_anglex<-
    cut(Sample_Pollution_and_wind_monthly$rounded_anglex, breaks = c(0,22.5,67.5,112.5,157.5,202.5,247.5,292.5,337.5,360), right = TRUE, labels=c(0,45,90,135,180,225,270,315,360) )

}