Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 237 | 212 | 241 | 235 | 237 | 236 |
| Tmin | 240 | 216 | 242 | 235 | 243 | 231 |
| Duration of sunshine | 171 | 147 | 165 | 165 | 171 | 166 |
| Precipitation | 185 | 176 | 187 | 180 | 185 | 180 |
| Humidity/Visibility | 179 | 155 | 173 | 174 | 175 | 173 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 240 | 244 | 259 | 262 | 261 | 271 |
| Tmin | 240 | 239 | 251 | 268 | 262 | 269 |
| Duration of sunshine | 167 | 171 | 185 | 200 | 197 | 205 |
| Precipitation | 186 | 192 | 212 | 211 | 211 | 221 |
| Humidity/Visibility | 177 | 177 | 195 | 205 | 201 | 207 |
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. |
