Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 118 | 123 | 108 | 118 | 100 | 89 |
| Tmin | 118 | 116 | 116 | 115 | 104 | 88 |
| Duration of sunshine | 115 | 116 | 115 | 115 | 102 | 88 |
| Precipitation | 124 | 135 | 121 | 131 | 144 | 151 |
| Humidity/Visibility | 121 | 125 | 113 | 118 | 126 | 136 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 65 | 58 | 60 | 62 | 54 | 63 |
| Tmin | 93 | 65 | 59 | 62 | 60 | 60 |
| Duration of sunshine | 93 | 65 | 58 | 62 | 59 | 59 |
| Precipitation | 152 | 159 | 154 | 153 | 152 | 157 |
| Humidity/Visibility | 132 | 144 | 146 | 147 | 141 | 148 |
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. |
