Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 171 | 152 | 175 | 168 | 171 | 167 |
| Tmin | 176 | 156 | 173 | 167 | 176 | 166 |
| Duration of sunshine | 268 | 239 | 298 | 288 | 301 | 286 |
| Precipitation | 202 | 182 | 210 | 187 | 198 | 186 |
| Humidity/Visibility | 162 | 145 | 161 | 156 | 160 | 157 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 175 | 172 | 201 | 197 | 194 | 201 |
| Tmin | 177 | 181 | 194 | 200 | 197 | 205 |
| Duration of sunshine | 302 | 305 | 316 | 292 | 318 | 329 |
| Precipitation | 198 | 196 | 218 | 229 | 224 | 237 |
| Humidity/Visibility | 171 | 172 | 192 | 186 | 183 | 189 |
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. |
