Monthly Data Summaries

The monthly summaries consist of the monthly means, from the three hourly data set, and the extremes, from the complete data set. For monthly values to be included, 25% of the three hourly observations must be available. Months with 50-75% of data missing occur most often when a station is started or stopped in the middle of the month. This can cause a bias in the monthly mean, especially during seasons when parameters such as temperature change rapidly. Annual means are calculated only when twelve months of data are available. The data are presented in the same order as the sites listed in Table 3.1. Definitions of the monthly data summary headings are listed below.

HeadingDefinition
Mean air temperature, deg C Mean value for the month.
Percent of monthly data missing Ratio of the number of missing observations to the number of possible observations X 100.
Maximum air temperature, deg C Maximum value for the month.
Minimum air temperature, deg C Minimum value for the month.
Mean wind speed, m/s Mean value for the month.
Percent of monthly data missing Ratio of the number of missing observations to the number of possible observations X 100.
Resultant wind speed, dir/vv Resultant speed and direction for the month.
Constancy. Ratio of the monthly resultant to the monthly mean wind speed.
Maximum wind speed, dir/vv Maximum wind speed and direction for the month.
Mean air pressure, mb Mean value for the month.
Percent of monthly data missing Ratio of the number of missing observations to the number of possible observations X 100.
Maximum air pressure, mb Maximum value for the month.
Minimum air pressure, mb Minimum value for the month.

The 1994 monthly summary information is available on-line.