Humidity is the measure of the total amount of water vapor in the air. Dew point temperature is the temperature at which air becomes saturated. Relative humidity is the total amount of water vapor in the air, compared with the amount that would be there if the air were saturated.
1. Mean Dew Point Temperature:
Mean monthly values are computed by taking the 30-year mean of the monthly means. The monthly means are computed from the daily values. The mean annual value is computed by taking the 30-year mean of the yearly means. The yearly means are computed by averaging their 12 monthly minimum daily dew point temperatures.
2. Mean Relative Humidity:
The mean monthly values are computed by taking the 30-year mean of the monthly means. The monthly means are computed from the daily values. The daily values are computed as the mean of relative humidity values for the 24 hourly observations. The mean annual value is computed by taking the 30-year mean of the yearly means. The yearly means are computed by averaging their 12 monthly mean values.