Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 204 | 191 | 208 | 225 | 236 | 232 |
| Tmin | 206 | 182 | 215 | 226 | 234 | 230 |
| Duration of sunshine | 76 | 58 | 73 | 84 | 89 | 90 |
| Precipitation | 117 | 113 | 134 | 147 | 142 | 137 |
| Humidity/Visibility | 81 | 72 | 85 | 101 | 107 | 107 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 234 | 233 | 220 | 215 | 220 | 223 |
| Tmin | 228 | 234 | 227 | 226 | 216 | 229 |
| Duration of sunshine | 85 | 94 | 93 | 75 | 83 | 91 |
| Precipitation | 153 | 139 | 135 | 122 | 156 | 159 |
| Humidity/Visibility | 103 | 106 | 102 | 87 | 94 | 101 |
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. |
