Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 150 | 129 | 129 | 118 | 120 | 113 |
| Tmin | 179 | 159 | 178 | 165 | 177 | 173 |
| Duration of sunshine | 178 | 154 | 171 | 162 | 171 | 172 |
| Precipitation | 190 | 174 | 200 | 193 | 196 | 179 |
| Humidity/Visibility | 128 | 113 | 121 | 115 | 118 | 115 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 115 | 120 | 143 | 141 | 140 | 149 |
| Tmin | 177 | 185 | 201 | 205 | 200 | 211 |
| Duration of sunshine | 173 | 183 | 200 | 205 | 200 | 206 |
| Precipitation | 194 | 194 | 220 | 217 | 216 | 221 |
| Humidity/Visibility | 118 | 119 | 138 | 139 | 136 | 140 |
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. |
