Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 1099 | 1011 | 1146 | 1109 | 1146 | 1140 |
| Tmin | 1101 | 1010 | 1146 | 1109 | 1147 | 1138 |
| Duration of sunshine | 90 | 83 | 91 | 89 | 96 | 118 |
| Precipitation | 124 | 113 | 127 | 121 | 128 | 150 |
| Humidity/Visibility | 96 | 91 | 122 | 118 | 126 | 149 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 1175 | 1176 | 1139 | 1172 | 1139 | 1152 |
| Tmin | 1177 | 1178 | 1139 | 1172 | 1139 | 1152 |
| Duration of sunshine | 119 | 120 | 117 | 116 | 118 | 123 |
| Precipitation | 156 | 157 | 150 | 153 | 150 | 131 |
| Humidity/Visibility | 154 | 152 | 145 | 143 | 142 | 127 |
Climate data is usually derived from meteorological data of a certain number of years. The actual number of recorded years may vary from only a couple to 50 years or more. The quality of climate data depends on the number of available recorded years. Fewer years means less reliable data. The standart-period for reliable climate data is 30 years. For example, the mean monthly temperature for, let's say January, would ideally calculated from a total number of 930 recorded January-days. However, the usual number of recorded days is much smaller. The table above shows the actual number of recorded days for every parameter measured. |
