Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 84 | 78 | 82 | 107 | 118 | 102 |
| Tmin | 86 | 72 | 81 | 106 | 119 | 108 |
| Duration of sunshine | 170 | 186 | 225 | 183 | 193 | 240 |
| Precipitation | 99 | 97 | 103 | 123 | 136 | 120 |
| Humidity/Visibility | 86 | 80 | 86 | 106 | 116 | 106 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 114 | 111 | 100 | 108 | 107 | 109 |
| Tmin | 116 | 117 | 108 | 111 | 101 | 105 |
| Duration of sunshine | 222 | 213 | 207 | 215 | 206 | 213 |
| Precipitation | 131 | 132 | 138 | 132 | 140 | 146 |
| Humidity/Visibility | 116 | 115 | 104 | 107 | 104 | 110 |
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. |
