Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 176 | 155 | 178 | 172 | 168 | 165 |
| Tmin | 171 | 152 | 172 | 172 | 179 | 165 |
| Duration of sunshine | 170 | 151 | 173 | 171 | 179 | 165 |
| Precipitation | 170 | 162 | 167 | 163 | 163 | 165 |
| Humidity/Visibility | 177 | 160 | 178 | 173 | 177 | 169 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 165 | 159 | 187 | 184 | 181 | 195 |
| Tmin | 168 | 158 | 172 | 168 | 180 | 195 |
| Duration of sunshine | 167 | 155 | 171 | 169 | 179 | 195 |
| Precipitation | 202 | 211 | 207 | 227 | 224 | 237 |
| Humidity/Visibility | 169 | 164 | 197 | 187 | 183 | 200 |
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. |
