Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 3297 | 2990 | 3307 | 3200 | 3288 | 3196 |
| Tmin | 3302 | 2992 | 3314 | 3204 | 3293 | 3202 |
| Duration of sunshine | 62 | 57 | 62 | 60 | 124 | 150 |
| Precipitation | 186 | 169 | 187 | 181 | 186 | 180 |
| Humidity/Visibility | 184 | 166 | 183 | 177 | 182 | 177 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 3303 | 3303 | 3227 | 3332 | 3233 | 3340 |
| Tmin | 3310 | 3308 | 3234 | 3341 | 3238 | 3340 |
| Duration of sunshine | 124 | 93 | 90 | 93 | 60 | 62 |
| Precipitation | 187 | 190 | 210 | 215 | 210 | 217 |
| Humidity/Visibility | 181 | 183 | 204 | 208 | 204 | 215 |
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. |
